They're such fun to own. I bought a batch of fry off eBay in December and never imagined they'd all survive and I'd have a tank full of active colorful fishies. I want to move them to the bigger tank but IDK how I'm going to do it. I may have to get a 10 gallon instead for now.
I don't want babies to overrun the small tank. I can put the extra babies in my 55, which has some juvenile Acaras and a medium/large Blood Parrot... But they'll likely be eaten.
Do you have another spot where you can set up the larger tank, and keep the smaller tank where it is as a nursery tank for fry/potential quarantine tank perhaps?
Livebearers are a lot of fun! I keep guppies, platies and mollies right now, but they often get overwhelming since they just produce so. many. fry. It's not a bad thing that you have some large cichlids for population control - at least for any deformed ones. Guppies and Endlers are pretty prone to producing the odd bent spine fry, and it's not good to let the deformed ones breed.
Otherwise if you just want to keep the adults and some fry in one tank, removing some fry when it gets too overcrowded, that works too! You can see if your LFS is willing to take the young when they're a bit bigger, mine accepts my overpopulation once they're 2-3 months old and large enough for them to sell. If you're going for a mixed male/female community tank, just keep an eye on the male/female ratios. Too many males, and the females get stressed and exhausted from being constantly chased. Too many females, popping out 30-40 fry each per month, soon gets overcrowded! So it can be tricky to strike a balance at first, and it's why a nursery tank to scoop a load of fry into can be handy!
If you'd like help/advice about how to go about moving them to the bigger tank, would be happy to help. You could make a thread for that. I hope you make a journal thread to share your progress with this tank and the new tank you're planning to set up! Love following people's progress when they're setting up a new tank, learn a lot that way, and your enthusiasm is really nice to see