[monster1000s]

A few of you may have already seen the video of my tank I posted a while ago (link below) it is a 200l tank with about 30 fish altogether, plenty of ocean rock, a Fluval 405 external filter, couple of heaters etc

http://www.youtube.com/user/bazandsam#p ... fWGWtPAFdU

Every week I do two 40% water changes vacuuming what subtrate I can access every time, my nitrite and ammonia, as you would expect, are both ZERO but my nitrate remains constantly high, very high in fact. I have experimented by doing 4 water changes per week for a couple of weeks, feeding less but nothing seems to make a difference!

The fish seem very happy, it is a very lively tank without too much aggression, they get fed twice per day and all eat very well so should I be bothered by this, if I should be what can I do to reduce this level?

Thanks for reading.

 

[zimmy]

30 fish is quite a bit for a 200l tank. With the amount of rocks you have in there (which looks great BTW), you probably have closer to 120l. If you're not cleaning under/between the rocks, the mulm could also be building up. Both of these issue would contribute to making nitrates hard to control.

The link below describes the nitrate reducing capacity of having the roots of a common houseplant immersed in the water. I'm about to try it. It sounds like it could be worth considering for your situation.

http://www.cichlid-forum.com/phpBB/view ... p?t=227220

Hope that helps.

 

[monster1000s]

@ Zimmy, The problem I have, as you have rightly identified, is the sheer volume of rocks. This set up took the best part of a day to create and that was in an empty tank all these rocks are individual and have to be precisely positioned to ensure their rigidity and safety, taking them out to vacuum with the fish still in their is just not an option. I do remove a few rocks every now and then and vacuum but the main bulk of the rocks, to the left hand side as you watch the video, just cannot be moved.

Any suggestion to remove the rocks vacuum and replace on a regular basis is just not feasible.

When I pour the water back into the tank during water changes I aim the water from my 25l water bottle directly into these rocks and put the water in with force to dislodge any waste so the pump can collect it. I also have 2 air stones at the back of the rocks creating water movement to ensure no waste settles there, it is inevitable that waste will build up over a longer period of time.

 

[prov356]

Possibly nitrates in your tap water? What level of nitrates do tap and tank read exactly?

 

[noddy]

When was the last time you cleaned out the Fluval ?
It maybe full of waste that is being pumped back into the tank. I just converted 200 L to gallons, and I came up with 44 gallons. If that is right, your tank is way overstocked IMO. Added to the fact that half the water volume has probably been taken up by rocks, I would have to say you are facing an uphill battle. I think Large, frequent water changes would be your only option.

 

[monster1000s]

The Fluval gets cleaned out every 8 to 10 weeks, a quick rinse around, maybe changed a little bit of the media so I'm quite happy that is all ok.

As for the overcrowding comment maybe you are right, some of you may remember but when researching this I went to lengths getting advice from both this forum and specialist fish shops around the country and about 25 fish and 5 plecs/cat fish (5 medium to large, 10 medium and 15 small) seemed about the right number. They certainly do not look crowded they all seem to have their favourite hiding places and there is a good area to swim about in. Of course at feeding time it is carnage but what do you expect! Maybe when the odd smaller one dies, as they inevitably do, I will not replace and aim to cut the numbers by 7 or 8.

I am loathed to remove some rock because a) I believe it looks stunning b) as you could imagine it's not cheap stuff!

 

[702Cichlid]

The only problem with extensive and intricate rockwork from floor to waterline is that a fish can die or waste can get trapped in it and you have no way of knowing or seeing it, especially in a tank that is overstocked. What I'd do is a large (50% minimum) water change, measure nitrates and then hold off feeding for 2-3 days and see what your nitrate creep is. If it moves up a lot without feeding then you have a nitrate source somewhere in that rockwork or filter.

 

[natedgg]

@noddy It's 52.8 gallons, but eh, it does still seem overstocked.

@monster1000s As zimmy said, the rock work (which looks great) does you in more than anything. As far as the advice you got from forum folks; I hope someone didn't misread and think you were talking about a "200 long", which, if they were American, would mean 200g long (potentially) to them and would be fine for 30 fish (and more!).

 

[natedgg]

Forget that theory, monster I found the post you were referring to, and yep, you spelled out liter's.
http://www.cichlid-forum.com/phpBB/view ... highlight=

 

[BillD]

8 to 10 weeks between filter cleanings on a heavily stocked tank is probably where the nitrate is coming from. Everything in the filter must be considered still in the tank. Removing the detritus, by vigorously cleaning all the filter elements in tank water more often will reduce nitrates. the solid materials are not consumed by nitrifying bacteria, but rather heterotrophic bacteria, which reduce the solids to ammonia. Remove the solids more regularly (before they can be broken down)and the nitrates will go down. In addition the two types of bacteria are both aerobic which means they compete for available oxygen. When a filter begins to plug up, the oxygen level goes down.

 

[noddy]

@noddy It's 52.8 gallons, but eh, it does still seem overstocked.

Lol, I was just talking about this the other day. We are both right. 53 U.S gallons = 44 imperial gallons.

So it sounds like a standard 55g tank. I think by the time you take into account the amount of rocks, you are probably looking at 35 - 40 gallons of water.

Monster, I understand where you'r coming from, I keep very heavily stocked Tropheus tanks and I am constantly battling nitrates. I am not about to reduce the size of my colonies so I must either change more water, or dilute the nitrates by getting bigger tanks. As of now, it's water changes. I just happen to be doing a w/c right now. This is a 5' 120g tank.

I do this once a week.

 

[PortiaD]

I think you are going to find that your tank is very overstocked as your fish get older and grow larger. The recomended standard is only 12 mbuna for a tank the size of yours and at that number it is considered overstocked, but acceptable due to their agression levels. So even if you only had mbuna which grow to 15cm (6in) you'd already be at over twice the recommended maximum.

However, you have also chosen some of the larger haps that are going to grow to very large sizes, up to around 33cm (12in) and it's recommended that species like your nimbochromis be kept in tanks that are a minimum of 473L (125gal). I bought mine an 795L (210gal) tank for when they ougrow their current tank.

It is also generally recommended that you do not mix peacocks/haps/mbuna, as the mbuna are typically found to be too aggressive and kill the others. Some people have had success mixing them longterm but from what I've read most people have not. I had a mixture like yours with my first tank, but quickly realized my error as they settled in and their agression revved up. So, I wound up buying a second tank of the same size to separate my haps/peacocks from my mbuna.

 

[monster1000s]

Once again I am very grateful to everyone for their helpful advice, it really is quite humbling that people take their own time to asnwer and help me with my problem, thank you.

To respond to a few of the comments made.

PortiaD - You are absolutely spot on when you say as the fish grow the tank will be way too small, this is a problem I realised when choosing the stock and in time difficult decisions will have to be made. I totally understand that I will have to lose fish in time, I will cherry pick my way through them, take into consideration all the facts, their rarety and behaviour patterns then do what the wife says!!

With regards to mixing speceis I was aware when I went into this what I was doing and, at this stage, it is a very peaceful tank, I have no doubt this will change as they grow but when this happens I will reduce numbers. The Hongi Red Top or Greshakei (not sure what it is) rules the tank and gives out fair and equal slaps to all the others.

702Cichlid - There may well be a dead fish in the rocks causing the problem, I am hoping that vigourously pouring the water back into the tank after water changes directly into the rock work would dislodge any carcases.

natedgg - I realised that being a Londoner some of my phrases and dialect may get lost or misconstude so I tried to keep it simple but apologies if I'm talking in riddles (or talking sh*t) to some of you!!

BillD - I will certainly take your advice on board, many thanks.

noddy - Dude that is one serious water change, I will increase my 40% to 75%, thanks mate

Thanks all, really appreciate you giving up your time.

 

[zimmy]

I just happen to be doing a w/c right now. This is a 5' 120g tank.

I do this once a week.

You're an inspiration, noddy!

 

[natedgg]

natedgg - I realised that being a Londoner some of my phrases and dialect may get lost or misconstude so I tried to keep it simple but apologies if I'm talking in riddles (or talking sh*t) to some of you!!

I think you were spot on mate

 

[BillD]

I failed to notice the original post came from London. Do you have high nitrates in your tap water?