Replacing Carbon Filter. Good Idea Or Not?

[ole tarantula]

I am in the process of treating my fish for fungus and have introduced a treatment after removing the carbon filter. I have replaced the carbon filter with a piece of sponge, cut to size.

Am I right in assuming that the sponge is a better medium to support bacterial growth than the carbon one? If this is the case I won't bother to replace the old one once my fish are better.

Will bacteria colonise any sponge?

What's annoying about this situation is that the tank has not finished cycling. Ammonia is zero but nitrite is 2 and nitrate 5.

Any advice is very welcome!

 

[crazie.eddie]

The bacteria should colonize the sponge. Bacteria will colonize any porous material placed in a tank.

 

[aaronc]

Carbon can be good for removing nasty chemicals out of the water, and can help reduce low level ammonia and nitrite, this said, a well colonised sponge will do the same with ammonia and nitrate

Aaron