When Will Swordtail Fry Develop Color?

[hunterlj]

Hello, I have a little over a dozen swordtail fry. They're a little under 3 weeks old and not showing any color yet. They're about the same size as my black molly fry that are not quite a week old.

 

[fluttermoth]

It's normally around the six to eight week mark, but different colours develop at different rates, so there's no way of telling for sure.

 

[hunterlj]

Awesome! Thank you. What's the minimum size tank I could use to raise fry in? I have 11 fish (2 swords and 9 mollies) in a 35 gallon tank that has plenty of plants and decorations and most of the fry seem to be able to hide just fine but I would like to get a second tank going anyways.

 

[fluttermoth]

Even though fry are small, they produce quite a lot of waste, as they're growing; more than an adult fish of the same size. I really wouldn't recommend anything less than a ten gallon.
 
You could use something like a five gallon, but you'd probably need to be doing daily water changes. Livebearer fry produce hormones that stunt the fish's growth once it reaches a certain concentration, so the more water volume, and the more water changes you do, the better the fry will grow.