Thanks for the advice . I have 3 guppies 2 ancistrus and 1 endlers livebearer. That's 6 tiny fish . 1 swordtail 2 Cory's and 3 mollies . Surely my tank can support these ?
Lemme show you how big mollies can get.
That's an adult guppy above them, for scale, and an adult platy below. Have three of these dudes in a 55 gallon community tank, and believe me, they use the whole tank. Check out the size of the adult gold dust molly behind them. The large black/blue mollies are at least five years old, and they're huge, voracious, and good swimmers, and aren't even as large as mollies have been recorded to get. Swordtails get even bigger.
It's like keeping you in a small ish bedroom for the rest of your natural life. Sure, you'll survive, but you can't go out and stretch your legs, or get any exercise.
Oh, and because mollies are mollies, they will eat as much as they can get, including any algae they find in the tank. Lots of food means plenty of poop, which can quickly give you ammonia spikes if you slack on water changes for even a week. And that's not even counting all the other fish you have in there.
It's easy to get excited as a beginner and want to stock your tank with as many fish, and as much variety as you can. But you have to consider the whole lifetime of the fish, and whether your tank is really big enough for their entire lifetime. It isn't, I'm sorry.