Depending on filtration, and current water conditions and a few other things, your tank might be at capacity now. That said, a female betta could possibly be added with little fuss. A male betta too, for that matter. This will depend entirely on the betta's personality.
I had a female in a community tank with mollies. Ulitmately I rehomed her. Bettas have a completely different diet than livebearers like mollies and platies. They're carnivores -- they eat mainly bugs and crustaceans and small fish and worms. Mollies and platies eat algae mainly with a side of tiny bug hiding in the algae. So you have to make sure you have the right food for both fish. Everyone loves bloodworms as a treat, but that's far more of a staple in a betta's diet, where I maybe give it to my livebearers once a month, if that.
Now there's personalities. Every betta is different. I have two males right now, and my child has a baby female. And there's the old female we no longer have. One of these males would never be able to be in any sort of community tank. He's attacked snails and nearly killed them when I've put them in to help with algae on the glass. He flares at mollies the next tank over. My other guy, Flash, is in a tank with African Dwarf Frogs. They get along for the most part. Except when the frogs decide to float into his bubble nests. Frogs don't speak betta flaring, much to his dismay. Both females had no aggression problem being in tanks with other fish. My child's is a baby, and is in a tank with neon tetras right now that aren't much smaller than she is.
Here's the other side: feeding. Mollies in particular are aggressive eaters. I had to pull my girl aside in the tank every time I fed to make sure she got her one-two pellets. And then I just sort of hoped she wouldn't bother with whatever was going on with the rest of the tank. Because it was a feeding frenzy. 99% of the time mollies and platies are totally calm tank mates. But put food in, and they're excited and want it.
Also, if you have a male molly or platy that likes to flare, a betta might not be the best choice to put in there. He'll may choose to flare and attack, simply because it's a threat to his dominance. ("No I still have the best dorsal fin I DO!")
someone pm me or help me cause I just really need help. I wanna do this right. Thanks in advance.
