When you get fry in your tank, the survival rate isn’t going to be the best, even lower if you leave them to free swim around or if you quarantine them in there own tank.
If you leave them in there, as they are, they may get eaten by adult fish, or they’ll get whisked up inside the filter.
If you quarantine them, you’ll need to add filtration and a heater, pre-heat the water to match the main tank temp where they currently are, and use cycled filter media, as a new filter would take weeks to cycle the new tank. Also moving them could stress them out and they could even die during the process.
The best alternative:
Buy whats called a hatchery, or breeding box to stick to the inside of the tank. These are usually a cheap plastic box frame, walled with mesh, or clear plastic with slits in.
This allows you to section off the fry, but you still get the main tank water, flowing through the hatchery, without having to set up a second tank. It also provides safety from the mouths of larger fish. The last advantage is that you can target feed the fry, meaning feeding them their own separate food without other fish eating it all before the fry get a chance.