sponge filters

[stp]

I am in the process of preparing an already established 75gal tank to house discus. Currently I have an Emperor 400 and an AC500 on the tank. I want to replace the Emperor with a sponge filter, but I have never used a sponge filter before. I like the Hydro-Sponge IV, but I am not sure what to run it with. Is a powerhead the best way? And if so, which one should I use? Thanks in advance.

Josh

[dannop]

I run those hydro sponges with a dual output air pump you can buy at walmart for about $10. The slower water flow from air makes for a better bacterial action of breaking down the accumulated waste. Powerheads will work ok but the waste collected with a larger water flow can outpace the bacterial action to break it down and you can end up with a bound up sponge filter in a relatively short period of time.

[RyanH]

I agree, an air pump with an air stone is the best way to go. I would also use a Hydro V in a 75 gal. tank. You can never have too much biological filtration.

[stp]

Sorry if this is a stupid question, but how does the sponge filter operate then? How are you getting water flow through the sponge or is it pretty much being used like bioballs?

[susankay1]

Hi STP,
The way I understand it, the air flowing through the center of the sponge to the bottom and back out through the center causes a suction effect that draws water through the sponge toward the center and back out. The water moving through the sponge is filtered by the biological bacteria that live in the sponge, resulting in clean water flowing back through the center of the sponge. I run 2-Hydro Vs in a 55, 4 in a 125 gallon, along with Aqua Clear 500's on each. Like they say, you can never have too much filtration. HTH Susan

[dannop]

Susan-that's the ONLY way to describe how sponge filters work!!! ;D

[stp]

Yeah, thanks for the info. I understand now :D

[Amadhunter]

It's really surprising how much water the air bubbles rising through the tube actuallly moves. The sponge filter moves water just like the under gravel filters do. As the bubbles rise, they expand, pushing water ahead of them thats trapped by the tube. The water in the sponge is replaced by the water surrounding it. :) Check out this pic:

[stp]

What size air pump would you recommend to run a hydro V?

[Amadhunter]

I use the dual output from wal-mart to run two of the hydro V's in a 75 gal. I don't think it really takes much pump to run them. I think the deciding factor is how deep the filters are. But the wal-mart seems to do fine. :)