I ignore all advice on betta tank mates and have one living in an endler colony that is set up in a 45 gallon tank. My other male lives in my 120 gallon community tank with 5 inch long rainbow cichlids, rasboras, black neons, some fancy angels, a few platies, a few nice standard size, not pygmy, cories and other things that I really ignore most of the time like the glowlight tetras. Most of the fish in that tank came from my wife saying something along the lines of "Can we get a few of those things?". I force my breeding molly to share the tank but remove her when I decide to raise some fry. In the last 3 years I have seen exactly one platy fry survive running the gauntlet in that tank. The betta is a fine upstanding citizen that really doesn't bother anyone. I can't say the same for the rainbow cichlids that have removed his fins completely when they decided to breed and he ignored their territories. The rainbows also dispatched my last nice male molly so right now they are not exactly my best friends.