Not two dwarfs..they wil pair if opposite sex and harrasss tankmates, if same sex males the stronger fish will eventually harrass the other to death if not outright kill it. It is One colisa or 3. Even three invites some aggression amongst themselves.
I am not sure why odd numbers in non aggressive fish. Usually odd numbers split a bullys attentions in semi-aggressives.
Gourami are not strict top dwellers as they are sold to be. They are wrongly classed so very often. They actually like to hang at the bottom unless they are nesting or swimming. And that means it may get to be a prob with your shark as it matures and gets testy. Clowns will out grow you faaast. You may need to check alternative loaches out..see the species index at Loaches online(
www.loaches.com). most are just as kooky and patterned and have smaller adult sizes.
My overstocked 40 has: BlackGhostKnife, 2 cories, 3 clowns, 5 Red phantoms
(small highbody tetras), 8 rummy nose,6 penguinfish (
finally counted now that they are all large I seem to have picked up quite a few wextra that day!) and then one out of place bettafish. Most move to a SA biotope this summer. As the tetra grow to tehir adult sizes it is getting crowded in the midwater.I wouldn't dare add my colisa to this tank or all heck would break out. The betta is at most risk becuase he is slow and must expose himself to refill the labyrinth organ. Lucky the tetra accept him well. so don't nip his long trailing skirts.
