Crabs

[matthrushford]

i have algae developing under my crushed coral. i have 5 crabs in my 15 gallon tank. how many more should i add?

 

[royal gang]

You should do a water change and figure out why the algae is appearing in the first place.

 

[farslayer]

I think about 1 or 2 per gallon is about right? Depends on how much LR you have as well, since that is where they will feed. Also, ditch the CC if you can, nothing but trouble later on.