I work in a pet store and the other day I found a little guppy fry in the female guppy tank. My manager said I could take it home for free since baby fish that we find here can't be sold. Today I went to work and my manager said he saw a baby molly or platy in the tank and after a little searching I found it and fished it out. When I caught the little baby he told me to follow him to the back. He showed me the tanks that sit below the fish wall that the filters empty into. He said "On occasion we find baby fish in there that the filters suck up. If you want to fish them out when you find them in there, you can have them." I immediately ran to get a net and today I rescued 5 baby livebearers. I'm not sure exactly what they all are. I know I have some sort of mickey mouse platy (I can see the little marking near it's tail) and one of them is silver/white. I have a 2.5g I can put them in for now. I have to go out into the storage and get my 10g out and clean it up.
Since I plan on fishing out babies whenever I find them, I know I'm not going to be able to keep them all. I will probably adopt out babies as I grow them up, but how many babies can safely live in a 10g?