Hello

Im considering filling my sump filter only with 30ppi filter foam instead of other expensive media for bio filtration. there is no lack of surface area on this and water flow is even through the layers. what am i missing here? why might this be a problem? I have a 130L tank and a filter volume of 15L.

Thanks

Sponges have to be fully submerged I believe.

Have you tried shredded PVC? I have a bag here that is enough to fill a standard 100g+ bio compartment. Im really not sure, I mean I know marineland's sumps work with filter trays then a bio wheel UNDER those but I really dont know if you can use a sponge as the biomedia or now, I use sponge filters and all that but those have to stay wet completely I know but not sure on pads because the top of my wet/dry's have pad trays and they arent always wet around the edges just pretty much in the center where the inlet holes are.
I do know my pads are 30 ppi and I am also very interested in ditching the bio-balls for sponge or the PVC.

it should work fine untill.... untill it gets dirty . you ll end up throwing it away or rinsing it extensively and thats when you ll loose all the beneficial bacteria .
I have ran 2 canister filters like that , but i never cleaned them at the same time and it worked fine.

Nylon Pot scrubbers 6 for a buck at dollar type stores. Excellent sump fodder.

Ultimately I don't think it matters what you use, just use something with a lot of surface area that can get "gunked up" with brown bacteria cultures and other crap from your tank. I use standard 30 ppi foam on my pre-filters and it's the best biological media I've ever run into.

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