Anywhere from one largish cichlid to 60 or more endlers.
I think southpaw said it better though. Tell us what you have for equipment, how long its been set up, what kind of water do you have, what fish do you like, will you be planing it with real plants, etc. It will help us to identify conflicts and suggest numbers.
Thanks guys. It's been set up for a week or so. Its got a heater, bio-wheel, fake plants as of now and I don't plan on ever getting more than one real plant. I got two Zebra fish that the LFS told me to put in there to get the bacteria going. I want tropical fish as in Discus, Pleco, Angels, just neat warmer water stuff. Nothing too aggressive like the Cichlids. From what I hear they eat the other fish. I just want some stuff that looks great but I want a healthy tank. I would like some things like an eel, cray, or other "cool" thing as well.
JM1212 Thanks for the link thats a good reference.
I just learned that cichlids are not one type of fish. I thought that Ocars were the same as cichlids
Well if you don't want cichlids that rules out both angels and discus. Also no crayfish, unless you aren't planning to add anything to the tank...
Some suggestions which you can research are the peacock spiney eel, the striped peacock spiney eel, the bristlenose pleco and the clown pleco.
By "cool" do you mean as in the odd and more unnatural looking fish? as in the oddballs? Or do you prefer brightly coloured fish?
If you want discus you need to spend a lot of time researching, they cost a fair whack to start up with, and take more maintenance then other species but are very rewarding.
Oddball type fish can include the african butterfly fish, the african dwarf frog and many other small fish that would be comfortable in a 55g. Kuhli loaches look extremely eel like and you could keep a school of them happily in a 55 with plenty of room for other fish. hatchet fish are another interesting fish.
If you like angelfish, you could do JUST a school of them, or just have a single one along with some oddballs.
Or maybe you'd like to have a tank with a single fish, such as a brackish tank with a puffer fish.
The best advice I can give you is to research research research, look at your local store decide what you like and go from there.
you would not be able to house a 'school' of angelfish.
angelfish will loosely shoal when not spawning..but a 36 is not large enough for more than 2-3 angels. also you would need a fairly large school of them as they will establish a dominance order.
which also eliminates Discus from the mix(btw both of these fish are Cichlids)
Discus while young you may be able to house 4 but they grow fast when cared for properly and you could only house 2-3 in a 36G. tank.
discus are shoaling/schooling fish you should house no less than 4 with 5-6 a better starting number..which means you would need a larger tank.
other peaceflu SA Cichlids to consider Keyholes. rams, Festivum, appisto's, flag cichlids(dwarf) maybe a blue acara.
but choose their tank mates wisely..these are all cichlids