[Trinitie]

Betta fish (males) can only be one male per tank, unless the tank is HUGE - and I mean HUGE. Males will attack and kill each other. They will also attack and try to kill any Betta female if they're not ready to breed. Males will also attack females after breeding has taken place. Many females can be put per tank, but only one Betta fish if it's a male.

Angel fish are fin nippers and will try to nip the fins of any other fish in the tank. Slower fish would be at high risk of being nipped.

Goldfish (in my opinion) are best left to smaller tanks that are easier to clean. Goldfish are known for three things: looking pretty, eating & pooping. Not much else.

If you'd like more information, I can PM you with fish that I'd recommend, and have had great success with in the past. Or, post which fish you'd like more information about and I'll see what I can reply with for you.