Checked your profile and see you have livebearers. My advice would be to do nothing. They breed like mad. Add some fine plants, possibly get some hornwort, and leave it be. Cover your filter intake with pantihose or something if you're worried about it. Sooner or later, a few will survive, but in a tank that size you can't save them all. Don't worry if that one doesn't make it, you'll have more next week. If you really want to, you could get a breeder net and try to put the fry in there, or put pregnant females in there, but if you end up saving too many you'll have to get more tanks. I once had three guppies in a two gallon tank. It was my first tank and I didn't know anything and probably did nothing right. Some of the fry that I did nothing for actually survived in cramped quarters with only a plastic plant to hide in, so even after one of the adults died, I ended up with four guppies in my two gallon tank. Ahhh! Too many fish. And I didn't even try.