15 years ago
These guys are quite flexible when it comes to tankmates, and as long as the fish is suitable for that tanksize and a peaceful species they should be fine. So most marine fish such as dwarf angels, basslets, blennies, cardinalfish, gobies and most fish that cannot fit a small clownfish into their mouth or an aggressive fish that won't bully them too much would be fine. I would maybe avoid the more aggressive fish in a 30 gallon set up though as that's relatively small for a marine tank. As long as it's not other clownfish, they're territorial towards other clowns!
I like blennies, banggai cardinalfish and gobies personally so i'd go for one of them hehe.
As for inverts, that will somewhat depend on what other fish you get, as long as it's not one with a taste for shrimp, maybe go for a shrimp? But without live rock you will have to carefully consider what your inverts will be grazing on. You will have to supplement them with food too! Turbo or Astraea snails would work I think though they would eat nasty marine algae too.
6 years ago
2 gallons per inch of fish is what i have always heard. I have 3 tanks all fresh water, and i dont have any problems with over crowding or water quality by following that rule, just keep in mind the potential growth of the fish..