Balloon Molly fry are growing slow

[kiddomagic]

okay, so my friend game me his balloon molly fry about 3-5 weeks ago and they look like they're the same size when I got them but just a TAD TAD TADDD bit bigger.
I cant tell a difference.
They've been in a breeder box since the day I got them
I feed them crushed food which I put a mixture of things:
-Tetramin
-Omega One
-crushed betta pellets - REALLY small amount of them, about 3

and thats it
btw, theres 8 fry

 

[Galligak]

If you want them to grow faster try turning up the heat and feeding them a bit more. This will make them get bigger!

 

[Shetland James]

Feed them more often, and on high protein foods like puttied egg yolk if they're tiny, moving on to daphnia and bloodworm.

 

[Bettacrazy]

I heard when in a small space growth gets slowed down. Because they look well fed...... Yeah I would go with turning up the heat and feeding a little more.