[zcfish]

for my upcoming sump project, I am considering using just poret foam. I will have three sheets of the foam with increasing density with no bypass dividing the sump in half. water drains into one end and pumped out from the other. very simple design. this also allows you to fill the sump water level higher comparing to conventional bio-balls which need to be exposed to air. of course leaving enough room for the back fill.

the tank will be 6x3x2.5(h), 325g and the sump I am considering is a standard 75g. the pump will be around 2400 gph factoring in the head. maybe a pair of pumps as there are two return holes.

any merit to this? I have never used poret foams before so here's a few questions:

how thick should the foams be?
how long do you think the foams need to be serviced? consider all the crud will be trapped in the foam.

 

[RRasco]

I would use a 4" thick 10PPI sheet. You could add a 10PPI and a 20PPI if you feel the need as well. My sump uses this exact setup with one 10PPI sheet and works wonderfully. They say poret takes a while to get dirty before you have to clean it, like 6 months to a year. I've had mine in about a month or two and it looks brand new.

 

[FishFlake]

Just to clarify, are you placing the foam vertically between the inlet and the pump?

 

[zcfish]

this is the design i have in mind. i discovered it after the initial post:

http://swisstropicals.com/Web%20picture ... filter.pdf

the foam will be standing vertical. I wonder for a 75g size whether the foam can stand by itself.

 

[zcfish]

I would use a 4" thick 10PPI sheet. You could add a 10PPI and a 20PPI if you feel the need as well. My sump uses this exact setup with one 10PPI sheet and works wonderfully. They say poret takes a while to get dirty before you have to clean it, like 6 months to a year. I've had mine in about a month or two and it looks brand new.

RR - do you see poop accumulates in front of the foam on the bottom as well?

 

[RRasco]

I don't see any accumulation. I would expect to somewhere, but not yet. It used to accumulate in the refugium and the return compartment, which is now crystal clear.

My sump is 12" deep and the water level sits about 12" as well. The 13x13 sheet worked perfectly for squeezing in there. The extra 1" holds in there firmly and prevents water bypassing the poret. I can post pics in a little when I get home.

 

[FishyOne]

I would suggest talking to the guys at Swiss Tropicals, they were a big help to me in determining foam thickness and porosity for my diy sump.

 

[Rhinox]

you might be interested to check out my thread: http://www.cichlid-forum.com/phpBB/view ... 3fea2b0cca

I'm doing the same thing you're planning on. My sump is a little different than yours, but same concept. Here's an image of what I'm doing with a 55g sump:

The 19.5x13 sheets of foam will work perfectly for a 55g. For a 75, I think you would use the 19.5x19.5 sheets of foam.

I emailed stephan tanner of swiss tropicals. What he recommended to me was to use a 20ppi 3" thick sheet of foam followed by two 30ppi 3" thick sheets of foam on each side of my sump. That would be 6 sheets of foam total. Stephan told me he estimated the sump could go for a year or more inbetween cleanings. Others have told me they have had great success with just one sheet of 10ppi foam filtering larger tanks than mine. So, still don't know what I want to do, but I know some point soon I'll be getting some of this stuff.

I haven't yet heard a good answer for what happens with all that trapped detritus in the system for a year. Seems like it would add to the bioload and nitrates would start to run away requiring larger water changes, but no one has been able to tell me to what degree that problem is. If I go with a multi sheet sump, I will probably rinse out the first sheets more periodically as they will catch most of the waste, and the second 2 sheets may never need to be rinsed.

 

[zcfish]

finally set this up. 75 gallon tank. water drains from the middle and two pumps at the ends. The pumps are 1000 gph actual measured at the outlet. One of the reason I run two pumps instead of one is that the slower flow across a wider surface will be optimum based on some article I read on the web about poret foam.

 

[RRasco]

Finally got some pics of my setup....I have since added 20PPI and 30PPI. I originally put them in there just to get them seeded, but I didn't end up building a 2nd sump like I planned, so they stayed and are working wonderfully!

When I switched this sump from one tank to the other I did notice some waste buildup. I rinsed the poret in tank water during the change and was on my way. It was no more build up than in a canister...you can see some buildup in the pores on the side.