Idea for discussion: "Live" Rock in a FW tank

[darkdep]

Just an idea from my failed SW Experiment...

In SW, "Live" rock is just a very porous rock, often dead coral, that houses lots of nitrifying bacteria.  SW tanks usually have lots of current, one of the reasons seems to be to have water moving through the LR.

Would this work in a FW Tank?  Lets say you took something very porous (DIY Live Rock maybe, or even "real" dead coral), put it into an established tank, added a powerhead to blow water over it, and slowly removed the existing biofiltration...I wonder if this would turn the rock into the biofilter?

Thoughts?

[bitterman]

I'm not sure how effective this would be. It might work to a small extent, but SW aquariums normally have much lower stocking levels, especially when you look/compare with alot of african cichlid tanks.

[kennyman]

I think the first two stages of biological filtration would happen with no trouble. I will actually go as far to say I know they will since I have a 10gal that supports three corries with NO filtration. I tracked the cycle of this tank so I know it was more than just the plants getting to the ammonium before it broke down. This was/is my Victorian experiment.

After reading Dr. Innes "exotic aquarium fish", first published in the 1930's, I wanted to see what it was like running a tank with only an airstone. Its about three months later and so far so good. Lastnight I got rid of all the contents of my 55 except for a little BN pleco. He will go in the 10 for now but I decided to add heat to the 10 (70deg). I don't think he can take the chill the cories can, so I am cheating a bit.

As for LR. The real deal with LR in a SW system is anaerobic activity. The conversion of Nitrate into a gas. But since you have to maintin heavy waterchanges in a FW tank for control of doc's I doubt if that part of the process matters much. You will be changing out water to maintain water quality so no big deal. Like B-man said though stocking will play a huge role in success or failure.