Internal Filter

[leonick]

I got an internal filter that has a foam sponge inside. its great because it filters small particles out of the water. After around a month, the yellow foam turns to gray / brown bec. of the stuff collected. Is this a "nitrate factory?" I noticed that airpockets appears inside the foam( I assume that it converted nitrates to gas) is this right? thanks

 

[Varga]

I learned the hard way that sponges are bad in reef tanks. i had a tiny tank with a sponge filter, I disturbed the filter accidentally and my corals closed for days!

 

[mps9506]

"nitrate factory" is a correct term. Sponges are wonderful filters but must be maintained properly because they are an aerobic environment all the detrius, particles, food etc collected on the sponge will breakdown into ammonia if left long enough. The aerobic environment provides a wonderful place for bacteria to grow that will breakdown that ammonia into nitrites and subsequently into nitrates. However because it is aerobic it will not process those nitrates.
Hence the term Nitrate factory.
If you are willing to clean that sponge every day or two feel free to use it. You only want it there to physically remove particulates, not for a biofilter.

 

[leonick]

thanks! but I notice air bubbles in the filter as time pass is that the byproduct of the nitrate bacteria converting it to gas?

 

[Varga]

can a physical filter actually catch and kill pods?

 

[sasquatch]

thanks! but I notice air bubbles in the filter as time pass is that the byproduct of the nitrate bacteria converting it to gas?

more likely just bubbles from rot, its warm, its moist its got bacteria all over it, not necessarily good ones.

 

[CMG]

I have a sponge filter in my main display because I am seeding it for a quarantine tank. Should I be cleaning it daily or every two days or leave it alone so I dont wash out the bacteria thats trying to seed?

Its been in there about 1-2 weeks and I haven't had a jump in nitrates.

 

[mps9506]

I have a sponge filter in my main display because I am seeding it for a quarantine tank. Should I be cleaning it daily or every two days or leave it alone so I dont wash out the bacteria thats trying to seed?

Its been in there about 1-2 weeks and I haven't had a jump in nitrates.

If you are not using it for actually filtering the water it shouldn't be catching detritus so you should be fine leaving them in the tank.