I concur. Gr8 filter! Gr8 price!

Easy to set up great on my smaller tanks.

High marks from the standpoint of effectiveness (mechanical plus bio, with two additional optional filter cartridge slots), ease of service/cleaning, quietness (contrary to other reports).
Noisiness only occurs after startup and while syphon is establishing...after that, it is all but dead quiet. I have never experienced continuous noisiness some complain about...I have no waterfall noise, as I keep water level above filter out-chutes, and impeller or cavitation noise could possibly be explained by incorrectly positioned impeller, or intake too low in tank allowing gravel particles to be ingested.
I have an E400 in service on a 55G 24/7/365 3+ years without issue one! I have added (and highly recommend!) the Mc Reynolds modification published under Library/Acquarium Setup/Power Filter "Tricks" on Cichlid Forum site (consisting of additional cartridges set up with aerated Sea-Chem de-nitrate rocks).
Very good experience with this product...good price/performance factor too!

These filters are probably the worst ones I have ever owned. I am afraid to clean them because they will never work quiet again. The plastic that it is made from feels flimsy and cheap. The replacement cartridges do not hold enough carbon and forget the low storage capacity of the media baskets. I had to break off all of the dividers on the inside just to fit in some bags of media (Chemi Pure and Purigen). When you install the cartridges and baskets all the material falls to the bottom and the water just blows through unfiltered.
The filters run terribly loud most of the time and at one point I had to unplug and take them apart to quiet them down several times.
Marineland has come up with a new impeller design which they sent me one and it improved the sound level.
Overall I am pretty unhappy with the way this filter operates and I think the bio wheel is just a gimmick. Too get anything that is manufactured solid in todays day in age is impossible to begin with. I had an Aquaclear on a smaller tank and the motor broke on this filter also.

I have 14 Tanks and all of the larger ones use Marineland Emperor 400 or Penguin 350 models. Some have been running for more than 4 years - 24/7. I've only replace 2 impellers so far. Any noise produced by these filters is from a poorly seated impeller or insufficient maintenance. Every so often, the intake assembly must be removed, cleaned and put back correctly!

As for Marineland Heaters, they went from best to worst! I've replaced all of them with Hagen/Jaegers and am quite impressed.

I've had the worst luck with these pumps. I find them very cheaply made, the filter cartridges are flimsy and even with scheduled cleaning the props would seize and shut down. Aquaclear has been great for me, for hang on filters.

I have 6 tanks running at this time, and have tried all types of filter options. Marineland filters are easy to use and very effective. I hang mine on the side of the tank so I get a nice flo across the top of the tank, and clean up is easy 10min filter cleaning.

I like these filters for the simple fact that they perform and perform well. As far as noise goes, my experience has been that some are noisey others are not. Check for bad impellar if it's Whhhhrrrr, whhhhrrrr I am a must for quiet filters and I have 2 400's on a 75 gallon in my home theatre room. I find the ambient noise in addition to the TV drowns the noise. The Bio-Wheels...? Love em. Been using this since 1999

I have been a huge fan of the Marineland powerfilters for years, they provide the best cleaning for its type and purpose.

The 400 really picks up a hefty amount of waste that i have not seen in the AC series (which i use as well)
The only down fall to the Marineland line is the expensive media, and loud noise.

They have great flow but it has one major design flaw...once the vertical media gets clogged up, water starts going around and over it...Aquaclear's do not have that problem and have a much superior design. The media customization options are not as good as the Aquaclear's either because of the design. I would choose an Aquaclear in any tank over the Emperor power filters. Even the minimum wage teenage dummies at PetCo and Petsmart recommend Aquaclear's over these since the price difference is so minimal for a huge filtration difference.

I've had 2 Emperor 400's now for well over 3 years and they have never failed me yet. Clears up a dirty tank incredibly fast and leaves it sparkling! Only noisy if you don't remember to seat the impeller correctly or the intake tube. Overall highly recommended to anyone.

misuse of aquarium filters is very common among hobbiest. Any negative reviews of these flters in my opinion is most likely due to lack of knowledge on how to use them.

I have a 280 on a 29 gallon tank

i like the filter, good solid workhorse, but it doesn't really suck up solids as well as i would like, water flows really well through it, but when debris flows by it just doesn't get sucked in like I would like

warning, it starts very loud and then quiets down after a while, be prepared for noise out of the box, but now it's perfectly silent

This is a great HOB filter. It's fairly quiet and cleans excellent. I wouldn't recommend any other HOB filter. A little on the pricy side but easy to clean and works like a charm. I've had it up and running for over a year, my friend had it up and running for 3 yrs. That's 4 yrs and I never, ever had a problem with it.

The Emperor 400's push a huge amount of water with NO bypass. There is a huge area to put in whatever media type you want.The plastic the Emperor's are made of is not a flimsy plastic that can crack easy like the Aqua Clears are made of. The spray bars on the Emperor's work great, other HOB's do not have the spray bars. Some will say they are too load, all they need to do is adjust the intake tube and the Emperor's are quite.

I've been using these filters for several years, and they truly are the best. If used correctly, these filters will keep your tank(s) crystal clear. The extra media basket allows for so many different options, and when combined with the "E" cartridge this filter is phenomenal. Remember to clean the spray bar monthly to get maximum wet/dry filtration from your unit. Emperor filters are the best, work the best, and should be used by serious hobbyists looking for the best filtration.

One of the best HOB filters I have owned. Keeps my tank healthy, clean, filtered, and well maintained. It also has a bio-wheel driven by a spray bar which acts as a mini biological filtration untit. I couldn't have owned better filters.

Decent filter but just really way too loud. I don't believe biowheels are really necessary for a clean fish tank and this filter is really just all about the biowheels. Otherwise, you are just getting two little cartridges which are expensive to replace. The filter is also much much bigger than you might expect. The noise factor kills it for me. Marineland sent me another impeller and the noise issue didn't improve. I would stick with their standard line of penguin biowheel filters and skip this one.

I run Emperor 280's on my 29g South American and 38g Mbuna tanks.
They were my first filters, and as a novice I have to say that they were incredibly easy to set up. They both run relatively quietly, but I like a light gurgle in the room - your tastes may vary.
I don't find that the filter cartridges last very long, but the extra cage can be stuffed with filter media of one's choosing - that cuts down costs since the fancy blue floss and carbon aren't needed.
One of my 280s splashes around a bit as water comes out of the intake tube - so much so that I had to build up a mini wall to keep it from dripping down the outside. One night of unforeseen dripping left about 5 L of water on my carpet.
My other 280 needs to have the filter box topped up during water changes or it just won't restart properly.
Both issues were easy to resolve, but my next tank will have canister filters.

I have had mine for about four and half to five years...never really had a problem with it...the only thing I have to compline about is that the spray tubes that make the biowheel move always gets cloged so the biowheel does not move and it kind of noisy I have mine in the living room and I can hear it all the way to my bedroom which is pretty far...other than that it does a very good job on my 60 gal african tank which has been crowed off and on with big fish....

The main complaint you will hear from people on here is that the replacement filter pads are expensive, and they are right they can be, but all you need is a little imagination. Just scrap the proprietary pads and get some bulk filter pad sheets and cut it to fit the extra gray media tray. And the idea of people saying the media clogs too fast... It is because it's a no bypass system! Anyone who is happy because their filter never clogs up... Well they are daft. It never clogs up because it is not doing it's job! Simply put they are the best HOB filter you can buy. I have one on a 29g tank with quite the colony of Julidochromis Marlieri Gombi's. And the water is crystal clear and tests exellent.

I used to be a big fanboy for these filters but over time and experience I have to come to realize that there are better choices. Marineland will sell you on the biowheels - you get a wet dry filtration capability in a simple HOB filter. Yes, it is a good design and I am sure it's effective - but in truth no properly stocked freshwater aquarium would require this feature. Especially if your tank is heavily planted as not only does it's remove CO2 from the water, it also forces the plants to compete harder for the ammonia since it provides such a good home for large bacteria populations. Plus the biowheel causes more evaporation. And in the winter or in dry climates, that means you have to top off more often.

But speaking for the filter itself it's a decent quality unit. The cartridges fit very snug and I am of the feeling that there is far less bypass with these than with Aquaclears or Whispers. But the downside is that these cartridges are pricey, and they don't last terribly long. (I've actually had two of them disintegrate when I tried rinsing them off for reuse.)

The lack of flow control is another downside. As is the often difficult process of restarting them after maintenance. My 400 can sometimes have me going bonkers with its inability to get flowing.

Though all in all, these are probably the most effective HOBs as far as cleaning the water is concerned. Though that makes for their favor, I have to say the cons sure do add up.

I own the Emperor 400 and it is on a 40Br. It works O.K. on this size tank but I probably would not use it on anything larger than a 55g. Its not quite as easy to maintain as other HOB filters. The Bio-wheel justs is not as effective as the ceramic ring type media. The filter is also a bit overpriced for what you get.

I've only owned penguin and marineland but I do have friends and family that own other HOBs. In my opinion they are all pretty much the same, but I would still not trade my emp400 for any other filter. It is easy to maintain, has 2 additional media baskets that you can fill with anything you want. It's been 3+yrs and I haven't had an issue with it. Great filter.

I have 2 emporer 400's on a 150 extra tall. they worked great when the tank was just set up and the fish were small. But cannot handle the larger bio-loads of the larger fish. The Lack of media in these filters deffinetely doesnt help. The bio-wheels are EXTREMELY OVER-RATED! Too much water can go around the media with all the unused space in the filter. Tank was always cloudy because it couldnt handle the bio-load, and the water would turn yellow after 3 days of a water change because of lack of media. I suppose it would be a decent filter for a 75 gallon or smaller. anything bigger dont waste your time.

Like the previous poster I use two 400s with a XP3 on my main tank, and find the 400s to be excellent filters. Maintenance is easy and you can with proper care use the same cartridge for several months. I recommend adding some filter floss in the provided media holders to enhance the mechanical filtration. You can also spruce up the bio filtration if you follow the directions in the article about them on this site, though I didn't see a need to.

I have been running two of the Emp 400's along with an XP3 and two 1140 powerheads on my 125 for a little better than six months and they do a good job. They aren't the quietest filter around and they could be improved but I like them better than the whispers I use on my 75.

Don't get me wrong, this is a good product. It keeps the tank clean, and the bio wheel does in fact build a large, hungry bacterial colony. The supplied empty grey frame is great for installing chemical filtration media. The 400 model keeps a 72 gallon bowfront clean. But the filter could be improved:

1. Like many hang on back filters, it could be a bit quieter.

2. The bio wheels need frequent attention. Snails jam them and must be removed.

3. As good as it is for bio and chemical filtration, it is only average for mechanical filtration. If there were more mechanical media (more or bigger pads), this would be a great filter.

To solve #3, I've taken to stuffing the grey chemical frame with cheap polyester pads, and placing them in front of the MarineLand cartridges. This adds the missing mechanical filtration, and extends the life of the Marineland cartridges (particularly for a big tank).

The noise is not bad, unless you try to use it in a bedroom, like another reviewer said.

Currently, I own an Emporer 400, and I have to admit that it is an awesome filter. Who needs to spend $400 on a wet/dry when you can buy a cheap yet effective one from Marineland. My ammonia and nitrite is practically 0 and my nitrate is maintained through aquatic plants and monthly water changes. It also cleans the tank with magnificent precision. I rarely see anything floating around, except torn off leaves from my cichlids, but they get sucked right onto the intake tube, and I go in later and pull it out. The only problem that I have noticed so far is that the Emporer is much more noisy than the basic Aquaclears and Whispers, but those filters also have crummy biological filtration. All in all, it is a great filter for a low price of $50.

I've purchased 2 Emperor 400 for $80.00 together. That is the best price I have ever gotten for a top notch power filter. Both filters cleans my tank very well. The only drawback I have with these filter is when I have a power outage or I shut the power off by mistake, the startup noise is horrible!!

I started my 70 gallon mbuna tank with an HOT Magnum Bio-Pro and an Emperor 280. The Emperor produced much more noise (both motor and splashing) than the HOT Mag. It does have a big bio-wheel but not huge like the HOT Mag is armed with. The Emperor also has a media basket for the media of your choice...I would put extra carbon since the cartridge doesn't have that much. Overall, I'd say it's good for mech and especially bio, decent for chem. This is something I would use on a 30-40 gallon tank by itself, but too noisy for sleeping in the same room. I replaced the Emperor with an Eheim 2215 canister...more money but I got what I paid for, and much quieter than the Emperor and even the HOT Mag.

I have used the marineland bio-wheel filters for 5 years. Bio-filtration is the most important. Chemicals are rarely needed. I seldom use carbon in my filters. The Emperor 400 provides outstanding bio-filtration with the large bio-wheels and bypass free mechanical/chemical. I've read some complaints about the cost of cartridge replacements. Cut the plastic grid, dump the carbon out before using the cartridge and rinse the blue floss weekly. You'll only need to replace them a couple of times a year. IMO these filters are (biologically) far superior to the canisters. Why pay more money for a complicated system. Most canisters offer great mechanical/chemical filtration, but also have a risk of leaks,less bio-filtration (even with large space for media)due to low oxygen levels in a closed system and time consuming maintenance. No matter what filter you use you'll always have to change water, vacuum substrate, and clean your filter. I prefer the maintenance part of the hobby to be easy. If it isn't, I might put off doing it. The Emperor is easy to maintain. Regular tank maintenance + huge biological/mechanical filtration=healthy and crystal clear water. Put ceramic rings in the media baskets for more bio-filtration. 2 or more E400's could easily handle a large aquarium 150+. They give better turnover than most canisters and cost less. No canister can touch their bio-filtration unless rigged up to a bio-wheel. Bottom Line: EMPEROR ROCKS!!!

I've been using the Emperor 280 for at least 9 years. I also have used the mini. The media is very easily maintained compared to the aquaclear. The refillable media container is a quick easy way to add additional filtration media. Some complaints I have with the 280 are the spray-bar is noisy, the minimum flow setting causes it to stop working and the replacement rite-size filter cartridge is expensive.

I have been keeping fish(cichlids) for over 10 years. I have used numerous power filters in the past and am sold on these. They might be a little more expensive but as far as hangon power filters, they are the BEST!! Highly recommend!!

Had a 280 on a 20g long for over a year and water quality is always great. Quiet, easy to use and trouble-free. As long as you change out the filter cart every so often you'll always have crystal clear water. And at $30/ea you can afford to have one or two extra on standby. Great little HOB filter.

Quiet, effective, continuous cost.
I have had mine for like a 1.5 years. It works, media for the filter clogs fast and is not cheap. Mine (400) take 2 cartridges each time.

My 75 ga tank has a support bar through the middle which makes for very limited placement of filter.

i use it in conjunction with a fuval4 and a intank CA1000 with a foam filter on my 55gallon tank medium clogs up but with all the filtration going on i change it about once every 6 weeks. like it

i just got the thing and it is loud! seems to do an excellent job tho ...extremely powerfull

Highly recommended for larger tanks. I particularly like the bio-wheel and double pump design. The first one allows higher efficiency of nitrifying process while the later one allows less food sucked into filter without compromising bio-filtration. Addtional space for media is appreciated. I personally suggest a Seachem Matrix for nitrifying and denitrifying and a black diamond carbon for odor and impurities removal. 9 for value/cost because it's a bit expensive.

Works great, especially if you fill the baskets with a good bio media. Put air stones in the bottom of each basket and hook up to a small pump. The air bubbles up through the baskets, aerates the media, and you have a wet/dry filter. Awesome bio filter. Remove the charcoal from the inserts and fill them with polyester fiber from walmart. When it gets dirty, take out the fiber and stuff some more in. Try it, it's simple and very effective!

Its a good filter, but the inserts are costly and get dirty fast, I make my own from
products from walmart. Also
I got a 3"X 5" sponge made by
big als and cut in half and
put in place of filter media.

I have not had a problem at all with these. Mine runs quiet and is easy to work with. I was using a HOT Magnum but after using this I will never get one of those again. Best bang for the buck in my book.

I have the 280 on my 29 mbuna growout tank. I dont like the noise it makes from water dripping[tank completely full] and the impeller get louder when slowing flow.Insert are expensive[ i make mine for all filters], and biowheels are very overated imo. Only got this one cause it was gave to me fromlfs i work at,Id never buy one. Save yourself some money and go with Ac500/110

I have the 280 on my 29 mbuna growout tank. I dont like the noise it makes from water dripping[tank completely full] and the impeller get louder when slowing flow.Insert are expensive[ i make mine for all filters] Only got this one cause it was gave to me fromlfs i work at,Id never buy one. Save yourself some money and go with Ac500/110

I got one as a 2nd filter and was So Happy with it,I got another to Replace the crappy one(topfin 60) that came on the Tank.
I'm glad that I found All the Good reviews! Was the main reson to get one,Thanks All!

i love this and have used it for my cichlid mbuna tank for about a month now and i can sleep wth it on perfectly, i need a quiet filter in my room and as long as your water level is perfect there is literally no noise. After and hour of putting sand in the cloudiness of water was gone, i love the use and the effectivness of the filter!!!

Used the 400 model on a highly stocked 55g.

PROS - It cleaned and areated water quite well.

CONS - Had repeated problems with a "scratchy" noise from the impeller area. The media baskets dont hold small diameter media well. Costly inserts. Cleaning the plumbing is a PITA too.

I ended up using a AC500... much quieter, easier to maintain and use.

Helped keep my fish alive for 5 years now

I love this filter they are all I use at home and all I sell at work. You can found them for $35-$45 online and $50-$75 in stores but they are worth ever penny. The replacement filters are a little costly in the long run but I love this filters. My only beef is if I lose power they are a pain to get running correctly.

I got it for cheap, but if you to the LFS to buy it, it would be a ripoff. It's loud at first and then quiets down after a few months.

I was using the emporer 400 on my tank 45 gallon tank for about 1-2 years and I was pleased with it. It is not nearly as quite as an eheim, but not as noisy as others claim.

As far as cleaing ability it was amazing on my 45 gallon. I first started using this filter when I started the hobby with a severly over crowded tank and it still kept all my levels down(lucky for me). the water was always clean and crystal clear.

The one think I did not like was the cost to replace the filter trays. Maybe I replaced them sooner than I needed too, but it got costly.

Overall I like the filter, and would recommend it for anyone that does not mind a little extra noise.

easy,great water quality,quiet

I've had mine running for almost a year now, and 2 emp 400's keep my water polished, and my bio-load in check. I cut 50 micron filter pads and fit them into the gray media trays, and use 1 on each Emp 400. This reduces flow some, but polishing is top notch, and it still sucks up the big bits as well. Cleaning is a breeze, and priming isn't an issue, just have to keep dumping water down the impeller shaft. A UPS is handy with any filter though to prevent disaster.

So, In essence I love these filters, maintain them properly, rinse out the pads, and you will be pleased with reliable and effective filtration day in and day out.

I have been using these filters for about 5 years with no problems. They work great. I use both the 280,400

Why can't a company just put out a "high" quality power filter that is "eheim quiet" without rediculous media options. the bio wheels are excellent and by themselves don't add any noise. I used to have a couple of penguin 330's (the old design with the helpfull back slide in trays that were excellent for carbon, etc.) but the new ones have lots of space but waste it on junky overpriced proprietary media. IMO just at least offer a top quality line that is a noise insulated motor/impeller housing that doesn't eventually start RATTLING!! I realize that they make money off the media much like printer companies make $$ off the ink cartridges but I would be glad to pay 100 or so for QUALITY, and be able to put my own fiber/carbon in. After all most of us are in it for the long hall and the extra dough for quality would be worth it. But what do I know, I just work here; or so they say........

I just bought the 280 after reading reviews here and on other post, plus I talked one on one with my local LFS's, man I tell you there is nothing like finding out for yourself if a product is worth the $50 you paid. As soon I hooked this bad boy up I started having trouble with it. The spray bar does that it spray's and it turns that wheel so fast it sparys water all over the place. And that extra fliter tray to put carbon in would be great if the slits where WAY smaller, you put cabon in there and it all falls out (what gives marineland), that stuff isn't fish food. The 280 GPH is great though and if Marineland can get this thing to quite down some and do something about the over size slits in the extra fliter tray then this fliter will be on the top. Oh yea and do something about the spray bar bar. So as of now, if anyone asked me if would I'd buy another one I would say heck NO! But that's my $0.02.

I had the Emperor 400 on my 55 gallon. Very reliable, a bit noisy, but excellent at keeping ammonia low. There's plenty of reviews on this filter, but I'm surprised no one mentions the pair of gray plastic inserts that allow you to choose your own media. I actually found that they were a pain. Difficult to close with media. It's almost impossible to fill them without being able to see right through them. It's great in concept, but poor in execution. I switched to an Aquaclear, simply so that I can more easily try various media alternatives without the hassle. Nevertheless, this filter was very reliable and capable of handling a decent bioload.

My first Emperor 400 is still in operation after 9 years. It has seen a host of other filters to accompany it and it keeps on going and doing what other filters only dream about. There are very few products that I feel this way about, but without spending large sums of money, you will not find a better filter. My only complaint however is the replacement cartridges. I have a huge pile of carbon in the bottom of the box. I really need the carbon in the cartridge. Please tell Marineland if you to have this problem. I guess everything can not be perfect.

tank stays clear all the time.

I originaly reviewed the Emperor 400 in 10/05. Since then it no longer has the flow control lever. so you cannot decrease flow when feeding and it no longer has the viewing windows to make sure the biowheels are turning. I emailed Marineland and they eliminated the flow control to decrease noise ?...Also they didn't say why they eliminated the biowheel view windows( my biowheels have stuck on several ocassions)also it now has a mid-flow intake which is silly..I think they did it to save a few cents on cost..I will now buy Aquaclears when I need my next filter...Cichlid forum should update there product description to eliminate flow controls...

I have had the same emp 400 running for 7 years and have only changed one impellor. I have made a few modifications and now this little filter is the sole mechanical filtration in my overstocked 125 gallon aquarium.

The best HOB filter ever made. Keeps water extremely clean and works very hard.

I purchased an emperor 400 for a 29g tank a few years back and it has been an excellent filter.. The filter
cartridges are larger than most hob filters and I really like the media containers that come with the filter. The additional spray bar to insure the biowheels won't stop is a very nice feature as well.. Overall, I've been
extremely pleased with this filter.. Anyone considering a bio-wheel hob filter, look no
further..This is the best biowheel filter on the market.
It is a little too noisy for bedroom use but fine for other areas of my home. It's a great filter, second only to the Hagen Aquaclear line.

This is a truely effective filter for any aquarists. Some would argue the AC500 is superior but that's misleading. The only reason why you would want an AC500 is bcuz it's cheap. AC500 cost less and their media cost less. AC500 is not a bad filter but not as good as people claimed it to be. I believed the E400 is far more superior. Good flexible plastic which prevent breakage if you accidently step on it or drop the lid. Large bio wheels with water spray bar to propel the wheels, holds almost 1gal, adjustable flow control, can be quiet if you tune it which I will specify how later, and it has plenty room for extra media. Be creative with any media you might want to add. Not to mention the design is very sleek and attractive. Yes, the E-400 can be noisey due to the impeller design. It's a dual impeller which means it has two impeller spinning at the same time. The key is to keep this impellar as clean as possible and be anal about it. If a small grain of sand get caught in between the two impeller then the impeller will rattle making a loud roaring noise. This filter is not recommended for aquarists using sand substrate. DO NOT ALLOW ANY SAND IN THE FILTER OR ELSE YOU'LL SPEND A GREAT DEAL OF TIME CLEANING THE IMPELLER. Cleaning is not the easiest among other filters bcuz you sort of have to be handy to know how to take it apart with easy. I have a mechanic background so cleaning is not troublesome to me.

had a problem getting it to prime but after 6 hours running, water is polished and fish are all over the place , I've done my research on filters and this is the best one for the money . won't change to caniser filters cause owner of lfs said canister filter are inferior to emperor 400 cost me 49.99 at hidden reef.com

so many arguements on which is best AC or Emperors, my experience, Emperors are the best money can buy, AC are the best for the money, any question?

I started out using the 400 and i have tried others but i always go back to marineland...there just isnt a better HOB out there...

My 1st aquarium was in 1971. I've used the corner, underground, and HOB filters. I have 2, Emperor 400's on my 75 gallon. As others has stated the media choices are numerous. These filters come with two optional use slotted plastic holds to put any type of lose crystals, charcoal, etc. you perfer. I am very surprised to see some members are having problems with noise. I would also have to state the only noise both of mine make is simply the water flood back into the tank, which sounds a relaxing waterfall. I did have to do some initial adjustments to make sure there was no loss media, or loss contections with fittings during assembly.
My biggest advice on the Emperor would be cost on the box of 4 replacement filters that can run $17.99 and in my case that's times 2. I recently found a website that carries the name brand by Marineland for less then $9.00, a huge savings. I haven't ordered them yet, so I'm not so sure about S & H charges, but I still think it would be worth it.

Makes some noise, but not as bad as they say. And quieter if you keep the sand out of them. Huge bio-wheels, spray bars, customizable media trays, holds over 1 gallon of water. What more do you need? Best filter I've used yet.

I have used Emperor 280s and 400s. Both are noisier than the Penguins and AquaClears I have used. The spraybar is supposed to aerate the water and promote growth of nitrifying bacteria, but it also makes the filter very noisy.

By Far these are the loudest filters I have ever bought. I picked up a 280 and the noise was brutal. If anyone is considering getting a Emperor 280, go with the Penguin 330 instead. Its a better buy, and doesint make as much noise.

"400 gallons per hour! Extra media storage! Large bio wheels with jets! Large bucket design! 3 Stage filtration!" The brag sheet says it all. I agree, it really is a powerful filter. If only it were quieter. It’s not really noisy, but it does make a mechanical noise. Still, if it's not in your bedroom, I would recommend it.

I got this to replace a LOUD and MESSY AC500. I am so glad I did. This is the BEST HOB filter i have ever used. I have it on a 55g tank along with a XP3. My water is crystal clear (not with the AC though). I is also VERY quiet compared to the AC500.

First i bought an aquaclear 500 filter for my 75 gallon tank,
As i was setting up It cracked on the side, I siliconed it and ran it for a day,
I was not really impressed, The intake sube was way up to the Right top corner of my tank which was not taking any debris.
I took it back, and exchanged it for an emperor 400
Boy is this sturdy, I love the biowheels. There is no noise as you would assume. The covers over the biowheels surpress everything, even some of the splash. I also love the Water flow control.
After 2 days i pick up the media tray and can visually see what has been picked up. Instead of fumbling with the aquaclear sponge as soon as i pick it up all of the debris falls back into my tank.

Great quality filter i highly recommend.

I have an Emporer 400 on a 90 gallon Malawi setup along with a AC 500. Easy to maintain, set it and forget it. Its best aspect is the media baskets that can house any type of media you choose to use. If I could change anything about the filter I would give the buyer the option of choosing clear intake tubing and filter over the black. Spend the money! It's worth it on tanks 30 gallons or larger. If you are just doing a small setup go with something smaller and cheaper.

I bought a 400 to replace the Whisper 60 which came with my 55 gallon tank since I didn't honestly think the Whisper could handle good bio-filtration. So far I am impressed!

The only sound from this filter is a little water trickling, no more noise that the silent AC 200 running beside it.

The only think I don't like about it is the ugly, black intake tube, but on the positive side, the intake strainer has small enough opening that even fry wouldn't get sucked up.

I just set up a 29gal with a Emperor 280 and it really seems to get the water flowing well. Love the spray bar feature which keeps the bio wheel from drying out when the flow knob is lowered for feeding.
Only thing I was disappointed in was the noise. Not the water noise but the motor noise. The drone from the motor is driving me crazy. Great filter for the living room, but won't be sleeping much if its in the bedroom. :)

pretty darn quite, takes some getting used to in order to figure out to quickly prime it and to make it nearly silent. Extra media baskets are very nice to have and the bio wheels are nice too.
Overall really good filter.
I am able to fit both carbn and filter floss into BOTH, not just carbon in one and floss in the other in the media baskets.
Definately would buy another one

I'm really tired of the Marineland filters!!! I've been a big user of their products for the last three or four years but I've had several filters just die out on me. I'm not sure why either. The impeller is still twirling around in all four of them but yet none continue to suck up the water to the bio-wheels. It was not until this morning when I noticed the latest casualty that I realized that I had 3 other dead marineland filters sitting in my closet. At the same time I have my whisper filters that have been running on my moms tanks for 6 years. These product suck over the long term but are great when they are working. I'd rather have something that I didn't have to worry about replaceing every 8 months.

i have run these filters for years now and think they are a good buy. they tend to be more noisy than the aquaclears, but also have some advantages over them. i plan to buy some of the cell-pore inserts, since i see that they are making them again. you realy cant go wrong with this filter.

I have 2 400's and they do the job very well. Doesn't require maintenace very often and after about 4 years I've yet to have any problem with them.

After some minor tweaking i hear nonoise at all from my filter. its bio wheels are super big and do a great job. onky gripe i think i have is the intake extender kinda stinks.. Owell
-Leewong

I've always used aqua clears, but after reading all the good reviews on the emperors, I bought a 280 and a 400 for a 90 gal. about two months ago.I don't know if I missed something in the instructions,but my tank is still not cycled, but to me thats understandable since there's really not enough volume,or area for beneficial bacteria to colonize, not to mention the fact that during water change, as soon as the water level drops about 4 inches they loose their prime and won't pick it up again until the level is brought back up to almost the level of the discharge, during which time the biowheels (what a joke) have dried out, destroying whatever good bacteria there might have been.I don't think a filter that looses its prime that easy is pumping as much water as it's rated at.They are both so noisy you can't hear anything in the same room (yes I've tried fiddlin with the intake to no avail).They say live and learn and these things have certainly taught me or I should say Reminded me that If it ain't broke--- don't fix it.I think 1 AC 500 would do a better job than both of these combined and all you need in them are 2 sponges,and they'll keep pumpin with a couple inches of water in the tank.

I have the emporer 330in my 37 gal bedroom tank. The 330 is super quiet and does a great job. The only thing you hear is the ripple of the water. It sounds like rain hitting the window on a lazy day makes you want to lay in bed all day.

I purchased a penguin 330 on line for 20.00 I tis deadly silent and very efficient on my 29 gal. I read a lot about noise with the 400's. Not so with this 330. You just can't hear it. Highly recommended

These HOBs are noisy like all HOBs, but the bio-wheel gimmick is not that, it actually works! They are well designed, and do a terrific job of taking out filth. I switched because I hated the Hagen Aqua Clear 500, and my Emperors blow them away. They may be cheaply made and somewhat chinsey, but they get the job done. Personally, I wouldn't pay retail, you can get a good deal on them through the better known aquarium equipment wholesalers!

Yes, it works great...but it is so loud that I had to take it down. The 1 Emperor 400 I had on my 75g tank was much louder by itself than the 2 XP3 cannisters and AC300 filters(put together) I have on my 180g tank. When Marineland solves the noise issue, this will be an outstanding filter. Until then...just not worth the aggravating noise--considering there are plenty of quiet and effective alternatives.

Currently the 60g cichlid tank has two Emperor 400s doing an excellent job of filtration. The filter is well made in comparison to equivalent HOB on the market. The plastic is of good quality with some flex in the material ridding the concern of breakage

The most oustanding feature of the Emperor series is from the large capacity of the basket(s) with the optional media trays. It is very simple with a little imagination to customize the method of filtration. The trays are great for coarse media, or toss in a media bag with finer media like carbon instead of the tray. Pressure fit a micron pad into the tray to better filter particulate matter. Use a pair of fine cutters to customize the trays to hold blue bonded filter pads to save on factory filter cartridges.

These filters really circulate alot of water, easily pulling out waste material from the tank. Use a micron pad and you will be surprised to see the results of the poop-factories you are keeping as pets.

The water flow knob is a useful feature especially during feeding; minimal, low, and high. The bio-wheels is quite effective since biological filtration is not lost when used filter materials is replaced.

The only drawback is the noise. Even taking into account that the Emperors are the size of some aquariums the spraying of the spray bars, the spinning of the bio-wheels, and the babbling of the water flow can drive some people nuts.

Great filters for your swimming poop-factories.

Oh man this thing is noisey. And where not talking waterfall noise, because there is virtually noi water noise because the water returns right at ao below the water line.

But the mechanical noise! I couldn't even stand to be in the same room with it.

If you're thinking you are going to load the media trays with bio media, I think you will be shocked at how little they hold.

If you can get by the noise, you can tweak this filter by eliminating the cartridges and replacing them with the media containers filled with floss and the loading it up with your favorite bio media.

But I'm telling you it makes one heck of a racket.

I've had my used Emporer 400 for several years now, never had a problem with them. Why does everyone complain about the filters plugging up? They plug up because they WORK, stopping most if not all suspended foreign particles. Why do you not have to change the filters as often on other brands? Perhaps they don't filter as good as you think they do, letting the majority of the particles recircualte as they simply pass through the filter. Personally I've run mine for well over 6 months and had no problems with clogging. It can be noisy if the water level is allowed to drop below the level of the outputs, but if you keep your tank clean and full you won't hear them ever. Water changes they lose their prime and then make a lot of noise as they churn what water is left in the resevoir unless unplugged. As far as getting them started again, it's best to not turn them on untill the tank is full. It takes a minute or so to get going, and can be helped by opening and closing the flow control "valve" several times to bleed the air out of the system. The bio wheels are great, never had a problem with them. Occasionally you get a little scum plugging one of the holes for the spray bar, but simply rubbing the bar with your fingers will clear them. The water outputs are right at the waters surface so you get a lot of surface water movement, along with a good current deeper in the tank. Hands down the best hang on I've used. Filters clogging simply me

I have used Emporer 400's for a lot of years and think they are a very good filter. Very durable, quiet, and keeps the water in great shape. Have used 2 on an 8 foot 100 gallon tank with no other filteration and does a superior job. I have never had to replace or repair any of them.

i have had mine running for six months now and have no complaints. it is quiet, reliable and does a great job.
very versatile filter is easy to clean and replace pads. bio wheels need zero maintenance. i like the fact that i dont have to worry about bio filtering now that i dont use a ugf.

I have been using an Emperor 280 for about 6 months and it has never failed. The prices are great if you know where to go. This filter is awesome and I would recommend it to anybody, beginner or advanced.

I have been using an Emperor 280 for about 6 months and it has never failed. The prices are great if you know where to go. This filter is awesome and I would recommend it to anybody, beginner or advanced.

I've been using an Emperor 280 for 6 months now and can't wait to set my new tank with the Emperor 400. Easy to use and maintain.

The Emperor 400 work great for me. It is very quiet. The extra media trays are great for adding a little extra charcol. It is a breeze to maintain. The only noise I have ever experienced with the unit is once in a while the lift up lid vibrates a little. All you have to do is adjust the lid.

I have four of the 400's and two of the 280's and they work great. The median baskets and GREAT. You can rinse the pads out and use them over and over to cut down on the cost of buying new ones. As far as the noise that others are reporting, all of mine are very quiet. I had one 280 that was a little noisy at first but after moving the intake around a little it has been fine. I love them.

I have been using one of these for 8 weeks and it will be replaced shortly. The media is too expensive, the pads plug up too easily, its too noisy, water output is weak and replacement media over time would just be too costly when on my other filters i havent needed to spend a dime for replacements in over a year.

Dont get me wrong,I use one(with some help).The bottom line is less water flow(gph) and higher priced.Do yourself a favor get an aquaclear.

i have had two of these, and they both work great. the price, at retailers is too much, rather, go to www.bigalsonline.com to get a great deal, these are worth the money. they are the best, the water in both my aqauriums are clear, crystal clear, no power filter is better

I have an EMP 280. i recieved it used. I have really had a problem getting it to suck up water but once it starts running it is really quiet. All I here is a trickle of water. I don't use any packaged filter cartiges. I have two trays that hold bulk carbon and a filter pad that I cut from a bulk sheet. Cheap, materials easy to replace, once I got it running properly it has kept my water crystal clear, with good movement and has been very quiet. I suggest, if your filter is loud, make sure it is pumping enouph water into the external tank inorder to keep the water level higher than the impeller blades. If the water level is high enough it runs as quiet as can be imagined.

Have a 400 on my 46 gal bowfront. Works extremely well and it isn't too noisy like other reviews state--I like the "waterfall" sound which is lessened if you fill your tank properly. The filter pads can be expensive (the carbon is virtually worthless) so, I cut out the blue filter pad and replace with bulk filter pads that I custom-cut and attach simply with rubber bands. I haven't used it with sand substrate though. I hear that's a problem if the sand gets into the impeller. All in all, a good reliable filter that I use in conjuction with a Magnum HOT that polishes the water and provides good water movement. Sometimes you can get the 400 on Big Al's for a mere $39.

Overall, a perfect filter for us.Sturdy,very effective and the noise doesn't bother us(We have a few "skilters") BUT,IT IS AUDIBLE.And it is VERY versatile.We use peat in one, crushed coral in a couple, ammonia chips in one and just the carbon pad in another.As far as price goes I have seen them for between $75-$110(which is insane!!) at my favorite mom&pop shops.I hate to say it but I have only bought it online for around $40 plus shipping.Ours are worth $45-$50 any day.

I ran an Emperor 280 for over 3 years and I have finally given up on it.

I HATE the filter cartridges. They are overpriced, especially compared to the Aquaclear sponges which are cheap and last forever. Furthermore, the filters design makes it very difficult to use anything but the proprietary cartridges. And, on top of that, the cartridges come with activated carbon inside them, which I prefer to not use on any of my tanks, especially those that are planted.

I also find that these filters are exceptionally large for the amount of media they contain.

The only thing I do like about this filter is the biowheel but since those can be bought as a seperate unit and attached to a powerhead or filter ouput, why bother with this terrible filter?

my old emperor was loud as #%$&. I think they made a change to them because my new one is totally silent, I run 2 of them side bi side on my 55.

I think that a bunch of AquaClear employees or stockholders have written reviews ahead of me. This filter is great, and except for the inital cost, free to operate. I saw that several people have written that it is too expensive. That's completely false. Don't buy new trays! All you have to do is take out the filter pad and wash it off in the sink and then stick in back in the filter. Also, if you want to use carbon and all that, then buy the empty gray trays, buy your carbon in bulk, and put it in there. No need to every buy the new emporer filters. I use the pads that came with it, and bought a 3x3 sheet of filter pad that I use for other stuff. Just cut some out of that and put it in the back, and now you have double your filtration. However, the biowheels are what make this product great. They may get a little warped and not turn as freely in a couple of years, but just buy some more or leave the cover on and you will never see it. The water basin in the filter is good in itself to add medicine or salt and know that it is evenly distributed throughout the tank. My only complaint is that it can be a little noisy, but jiggle the main intake pipe around, you can get it to where it is almost silent and all you hear is the water flowing from it into the tank. I think it is priced about $20.00 too high, but I'd rather spend that than get an Aquaclear without a biowheel for less. I have owned both and will never buy another Aquaclear again.

My feelings toward the emperor line are mixed. I am comparing this filter directly to its competitor the Aquaclear line because for most people that is the toss up. For one they are noisy when compared to Aquaclears. They are expensive to maintain because their filter pads are not reusable (for the most part). They are annoying to do water changes with because once the water line goes down a quarter the filter will shut off, this is not the case with the aquaclears. They biowheels tend to smell ocasionally. 2 things which the emperor does well is it handles sand better then the aquaclears and I haven't had one stop working because of this and they can handle a tremendous bioload.

These filters are too noisy for me. Even with the water line all the way up, its still noisy, I like a nice silent tank. I would never buy another filter that doesnt have reusable media. It's just a waste of money to buy cartridges when a sponge lasts for years. My impeller was noisy. I called Marineland and they agreed to send me a new impeller, but they screwed the shipment up and I recieved the wrong parts. By this time I had converted to Aquaclears, so I just threw the Emperor away.

this is a great filter...a friend of mine talked me out of an AC and into one of these and i'm glad she did....the biowheel and extra filter tray make this an even better filter....

I unfortunately was talked into buying one of these (emp 400)when I first got my Oscar, and it worked "ok" for about 3 months, now it constantly needs cleaning and no matter what it makes an ungodly noise, whether the flow rate is turned down or is max. The extra tray is a good idea, but for the $ and the noise; I would never buy another one again.

This is the best hang on back power filter I've ever had, and I've been using them all my life. I have an Emperor 400 on my 55 gallon and it keeps the water crystal clear. This and I haven't even used the included extra media trays, which I have to say have the capacity to hold a generous amount of extra filter media of your choice. It was a nice surprise after buying the filter. It can be marked up pretty high so look around to find a good deal. The internet is probably your best bet. If you have to buy it marked up, it's still worth it.

I've been using the Emperor 400 on a variety of tanks for the last 2 years, and I have absolutely no complaints. If set up properly, the only noise is a small trickle of water running of the bio-wheels. It has kept my tanks crystal clear and is extremely easy to set up and maintain. A bit expensive, as are the replacement filter cartridges, but I've been ordering them online for less than half the price I can buy them locally.

Some say these filters are noisy, I am running 6 400's and 2 280's in one room and I still hear the clock ticking on the wall. These guys really move some water....Unsurpassed filtration in my opinion...I won't buy any other powerfilter.

This filter is a workhorse. It is a silent filtration system except when flow regulation button is pulled hindering detritus getting into the filter. Other than that – silent! The filter media provided by Maryland is somewhat weak and costly. But, you can easily go around that subject. There is a lot of filter space that can be utilized by buying your own filter mats according to your specific needs. For this reason, this filter is easily souped up to handle most tanks specifications. I keep CA cichlids - they put the Emperor filters to the test and they handle my tanks with excellence. A great buy!

Best power filter I've used plan on getting another. Not as loud as every makes it to be.

Extremely easy to set up and clean. Extra filter media baskets are great for adding additiona biological media.
Bio-wheels work great in adding to the overall biological capacity.

My first filtration device was a canister but not anymore. I have two 400's on my 75 gallon and I have never been happier. For added filtration I stuff white course filter media into the re-usable containers that come with the filters that are used for carbon and just rinse them out every water change in dechlorinated water. The maintenance is easy and very quick. Also got to love the two bio-wheels that come with the 400. Overall I have nothing bad to say about this product. As for the noise, its just like having a waterfall in your room; I haven't had any problems with mechanical noise.

I got a 400 for added filtration and bio filtration for my 125 gallon and it works great. I would recomend this to anyone.

this is a great filter,easy to use just plug in and presto clear tank. excellent biofiltering and i for one do not find it noisy.highly recommend.

I have an emperor 400 on my 125g. It's real easy to set up and use, and keeps my tank crystal clear. I have'nt had the problems with clogging, I just rinse the cartridge wevery water change. I bought a Emperor 280 for my 30g. tank, swapped the established bio-wheel w he 400, and quickly cycled in the new tank. I like it alot, and will probably buy another for my 50g.

This filter excels at biofiltration and is adequate at mechanical filtration. Beyond that, there is not much to recommend it. It is expensive to operate, difficult to maintain, noisy, and the design is overly complicated, which increases the chances of failure. If the Aquaclear were not on the market, perhaps the Emperor would be a good choice, but the Aquaclear is on the market.

nothing but problems with this thing from the start. they are loud, and the pads plug up way too easily for the hefty price tag on em. on top of that, the thing is nearly impossible to prime. ill never buy another as long as i live.

This thing rocks. Do a search on "aerated substrate" for the secret to enourmous biofiltration for about $15 extra dollars.

It's NOT hard to prime, it's just not self priming. Fill the media section with water and start it up, there's no trick. It can be a little noisy when I bypass the main filtration to avoid sucking up all the food, but this reminds me to turn the main filtration back on when dinner's over.

Overall I like the filter but there is always the impeller noise. Also the pads clog quickly but not as fast as my penguin 330. I like the extra media basket which I stuff with pillow stuffing for extra mechanical filtration. One downside is that it has to be shut off when you doing waterchanges since it won't suck up water when the level goes down. It drains right after you shut it of but alsways starts up again by itself once the tank is filled and the filter turned back on

I'm using an emperor 280 for my 38. It has good flow, the media is pretty effective, and the extra tray is a cool idea. The bio-wheel probably does what they say it does. But I picked up an AC300 with some gift certificates I had, and I'm really kind of bitter that I spent the money on the Emperor. The AC just seems to be a simple, more effective design at half the cost.

Greatest power filter i ahev ever used. SO simple to use. Got mine for 40 dollars at bigals. Keeps my 55 gal crystal clear all by itself.

This is a great filter that is good for both mechnical and biological filtration. Media catridges are nice. I used filter floss in the media cartridges and cellpore behind those.

I have the Emperor 400, which has 2 bio wheels, 2 filters and 2 "baskets" behin each to hold additional filter media. What I like best is that it has a flow controll valve. I use this combined with a Penguin 125 in a 55 Gallon community tank.

I have a Emperor 330 with biowheel for biological filtration with an adjustable spraybar to turn the biowheel. Relaible filter, very east to change cartridges, and I really like the eextra media container. In constant use thus far on a fairly heavily stocked 46 gallon community tank with no problems. I wish Marineland put this same spraybar on their penguin filters as I have found the penguin 125 keeps the biowheel spinning poorly once it is well colonized.

It's not worth it, it's hard to believe the pump what they say they do....And sure are expensive for what you get!!!

an excellent fillter for almost all aquariums. easy to use, great bio filter, and versitle opptions. if there is one draw back, its that its hard to use on a planted tank: the bio wheel produces too surface disturbance resluting loss of CO2. still, it's on of my favourite filters.

this product when used according to directions is unequalled among hang on the back filters. those who have said that they have a problem paying for the replacement cartridges which tend to clog easily, obviously havent discovered the buy and modify method involving polyester batton 6$ a yard at any local sewing or fabric retailer. i have never had a problem with this filter and i find it extremely inexpensive. as far as water clarity is concerned it doesnt have a rival when used in tanks below 80 gallons. this product is simplicity personified...

I have no complaints. I have a 280 and a 400, and both do a great job. They get noisey sometimes, but it usually goes away after a few days. I've never had a problem with them, and rinsing the filter cartridges can extend their life and cut down on replacement costs.

The biowheels provide excellent biological filtration. I like the cartridges where I can change my carbon, or put in another media if I prefer. These filters are easy to maintain. I do wish that someone would make some "generic" (cheaper) filter pads. A special advantage that I have found is that when you want to start a new tank you can transfer an established biowheel, and stock immediatly, as no cycling will be needed.

that little switch on top is great for feeding time.i prefilter water so my filter doesn't get dirty and then u slice open the top and replace your charcoal

The reduced water flow feature is great and reduces the amount of wasted food. Pads clog quickly, but you can find it for $35 online, making it a good value

though many love these filters i can not say the same. they are noisy and very difficult to prime for an allegedly "great filter". i like the bio-wheels and think that they are great for bio, but the filter pads clog quickly and are expensive to replace.the supposed "ability to reduce water flow for feeding" i have found to be terrible. when you reduce the flow the filter chugs and gurgles like an old chevy. buy an Aquaclear, they are cheaper, easier to prime, less noisy, and filter the water very efficiently

The emperor is a very adequate filter. I used to run 2 on my 75 gallon tank, and they did the job well. They won't make your water crystal clear - but I haven't seen a powerfilter that does. These are very effective bio-filters, and I would trust them completely to handle the bio-load in my tank for years.

If you want perfect water clarity pay for an eheim.
If you want a good filter that will keep your fish healthy and your water "nice" for a lower price, this is your filter.

I've used Emperors for years and have been very happy with their performance

I've used them for several years and still have a hard time paying for the replacement cartridges. I love the idea of being able to add your own filtering media but the pads DO clog up too fast.

We have a bio-wheel 330 on our 45 gal tank and we couldn't ask for anything better. The water is crystal clear, and our chem readings are always perfect. The wheels are a great source of biological filtration. We rinse our filter packs when we do water changes. They clean so easily that we replace them avery 2 months instead of every 1!!!

I run two E400's on a 75G. My tank is stocked with 15 Mbuna and Victorians which average about 4". To keep costs down I don't buy the refill cartriges. Sure there are better filters on the market but for me they have been very effective, very easy to maintain and very easy to afford.
One downside is the noise. If you want a silent filter this isn't the one for you. The waterfall isn't loud but you can hear it. No doubt it will bother some people.

I had several of these filters when they first came out. I was never more disapointed in a filter since i started keeping fish. They are noisy, hard to clean, and the cleaning is a never ending thing, the filter media fills up way to quick, and is the most expensive on the market today, making it a costly filter to maintain. They move water only so so, i doubt if they really do live up to their specifications.

I got rid of my Fluval 404 's and bought 2 Emperor 400's. These provide great filteration and ease of use. I really have no downfalls except the filter cartriges do not last long. Great Filter!

I have 2 Emp. 400's on my 125 gal. tank along with one AC500. The bio wheels are unmatched for bio filtration and the mechanical filtration capabilities are bettered only by the AC500. Can be a little load but well worth it.

I put foam in one of the extra media trays for more mechanical filtration. I also put crushed coral in the other for buffering.

On large aquariums I recommend using Emp. 400's with a AC500 for that one two punch.

I've had three of the 400's and also three of the 280's. I have a couple of gripes but overall I think these are excellent products.

The filters are easy to maintain. I put four cartridge's in my 400 and just change/clean two at a time to save bacteria on the other two. The bio-wheels also greatly increase the bio-capability of these filters.

My only complaints are they can get noisy. I had one stubborn 400 that the only way I could get it to quiet down was replacing the impeller assembly. Lots of times you have to fiddle with the flow-gate to find just the right spot to get it to quiet down.

My other complaint is because the intake stem is so wide it lose's it's suction when ever doing water changes and the water level goes down some. I've had Aqua-clears that could suck no matter how low the water level but not these. Then when you do unplug them all the water in them drains back into the tank requiring you to have to fill them up to get them started again.

Even with these minor complaints I'd still say these are hands down the best power filters one can buy.

I have (2) Emperor 400's in my 55 gal tank, and love them. They were easy to set up - took about 10 minutes. They run quietly - just make sure you fill the chambers with water before you start them up. . . if it does get a little noisy (humming and sputtering a bit) - try unplugging them, then powering them up again. Worked 4 me.

I got mine from Big Al's - lowest price around for 'em.

I love that I have (2) cartridges and (2) media containers in each 400. Gives me the ability to add whatever medias I want. The biowheels run good too - just set 'em to run slow and you're good 2 go.

They're very effective.

Maintenance isn't 2 bad - they recommend u take 'em apart every month or 2 to clean them thoroughly - it doesn't look 2 hard - everything accessible and easy to get apart and put back together again. The impeller is easy 2 get 2 if u ever need to replace it.

The 400 mixes up the water really well on top. There's alot of aeration going on.

As far as flaws, I can't really see any yet - although I've only been running mine for about a month now.

Still, I love these bad boyz.

I highly recommend the 400.

This is the best power filter on the market today .Easy to use . It's got two media baskets . Any way you want to use them.You can even take one out and switch to cell-pore media. (Which i have)