School of chromis in a 20L?

[pottsburg]

I've got an established 20L with ricordea, brown polyps, and some xenia. As far as fish, all I have are 2 turbo snails, some hermit crabs, a damsel, and a lawnmower blenny. I'm planning to take out my damsel and replace it with some fun fish for the tank. Would a school of 5-6 chromis be too much on the bioload? Would I be able to add them and a pair of cardinals or would it have to be one or the other? Thanks ahead of time!

[axia55]

5-6 Chromis along with the Blenny would be WAY too much bioload on a 20g unless you have a huge skimmer and fuge. I would say the Blenny, a Chromis and 1-2 Cardinals would be pushing it (again, assuming you have "normal" filtration on the tank).

[EdKruzel]

Chromis in a small tank will eventually pair and kill the others of the group.

[oneoffcustom]

+1 with ed. I have bought 3 chromis twice and afte a week ended with two, and in one case just one.