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Discussion Starter · #1 ·
Anybody have experience with these?

http://www.marinedepot.com/filters_pur_ ... er-ap.html

I'm interested in knowing how you'd set them up. Specifically, I'm curious about the plumbing set-up, type of pump used and where the pump is connected (at the intake or outtake of the filter). If the pump is connected at the intake, I'm also interested in knowing if having a sand substrate is a problem.

Thanks.
 

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You can use it with sand, so long as the filter body is used on the suction side of the pump. This way the sand would have to get pulled through the media before making it to your pump which isn't very likely provided there's no bypass occurring.. You still want to try to avoid getting sand in there if you can help it, though. Maybe placing a small foam sleeve on your intake would be an added layer of protection.

As far as what kind of pump I would use, I would use some sort of mag-drive centrifugal pump on it. I don't know what would be the best brand to use as far as being quiet, etc. but I'm sure some of the resident experts can help in that arena.
 

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I've always heard that it's never a good idea to restrict the intake of a pump, only the outflow. Pools have equivalent, but larger cartridge filters and the filter goes on the pump outflow side. You should be able to use a variety of different plumbing materials, whatever is easiest for you and you're most comfortable with. I like PVC myself. Flex PVC is available if you want to make sweeping ell's and not have to deal with as many fittings, etc.
 

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prov356 said:
I've always heard that it's never a good idea to restrict the intake of a pump, only the outflow.
This is correct. The reason is if you restrict the inlet side you create a lower pressure on the inlet which can cause cavitation of the impeller and shorten the life of the pump.

Pumps are designed to deliver a constant pressure differential for a given fluid. There is never any harm in increasing the outlet pressure (as long as there is flow... you don't want it stopped) since the pressure differential across the pump is constant for a given fluid and temperature.

The pump doesn't know what the cause of the increased outlet pressure is nor does it care.

edit: I should clarify... the pump actually doesn't "see" an increased pressure on the outlet side. It delivers its outlet pressure right at the pump outlet regardless of what happens downstream. The way the pressure profile looks in the outlet pipe is not a concern of the pump.
 

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I can agree there, but that is not to say that 'pull' configurations aren't ever used in filtration.

Think about the Fluval 305 canister for instance. The pump is in a 'pull' configuration where it brings the water down through the side where the foam media is, before pulling it up through the baskets on the other side, then the pump.. This protection for the pump is an added benefit of that system.

All this said, I suppose the best idea would be to set it up as the manufacturer recommends. I tried to find some info on their site, but to no avail.
 

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Yeah the real issue is what is the pressure drop in that canister? If it reduces the inlet side pressure more than the pump is designed for you'll get cavitation. You'd need to consider the case of clogged media too.

I'm sure the Fluval filter was designed with bypass channels for the case where the media gets clogged. Those channels probably help insure the inlet pressure never drops below the specified minimum for their filters. They provide an all in one solution so they can engineer it specifically for that case.

You might be able to stick that canister on the inlet of a pump and it might run fine. It'd be a lot safer though to put it on the outlet side. You'd hate to come home one day to a completely destroyed pump due to cavitation.
 

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I say call the vendor. I believe they are pretty knowledgeable about their items. At least they were back when my friend worked there.
 

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dotbomb said:
Yeah the real issue is what is the pressure drop in that canister? If it reduces the inlet side pressure more than the pump is designed for you'll get cavitation. You'd need to consider the case of clogged media too.

I'm sure the Fluval filter was designed with bypass channels for the case where the media gets clogged. Those channels probably help insure the inlet pressure never drops below the specified minimum for their filters. They provide an all in one solution so they can engineer it specifically for that case.

You might be able to stick that canister on the inlet of a pump and it might run fine. It'd be a lot safer though to put it on the outlet side. You'd hate to come home one day to a completely destroyed pump due to cavitation.
I can't say I disagree with you, having the right pump is the key here provided that the manufacturer says it's ok to run in that configuration.

Aside from all that, it seems like a pretty nice filter and on their web-page I noticed they have an accessory that allows you to basically stack them for greater capacity. Interesting concept.
 

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Discussion Starter · #9 ·
Thanks for the responses everyone. I'll call the company on Monday and update this thread around their recommendations.

My objective is to improve the mechanical filtration on my tank. I have an Eheim 2262 but have noticed that unless debris happens to float right into the intake, it'll just move around in the tank until it eventually finds a resting place between some rocks. I've noticed debris floating within half an inch of the intake and it'll keep floating on it's merry way. I see why Eheim's reputation is built on their biological, not mechanical, filtration capacity.

I know I could get an HOB to help address the problem and that the Nu-Clear route will be more expensive but I want to fully research my options before I settle on something. I also have to admit I like the idea of assembling the Nu-Clear filter and having another project to tinker with for a while.
 

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I like this idea for mechanical filtration as well, I have thought about using a similar filter that's used in older hot tubs with a 110v circ pump. I like the nu-clear system but being in the spa business there are cheaper way's to go. The price for their refill filter is pretty high considering it is only a spa filter by the looks of it?

You might research some spa part retailers and see what might work for you, there are a few brands of circ pumps with different gph ratings out there that would work fine. My guess is that's what type of pump they might suggest. Like Swerved mentioned also most of those pumps are mag driven very quiet. I will do it at some point just have not gotten around to it. Would love to hear what they say!
 

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Discussion Starter · #11 ·
I got in touch with the manufacturer and was told that the type of pump I use should have a head pressure rating of at least 16' (7 PSI) and be rated for at least 500 GPH. Can anyone suggest something?
 
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