Ive been told that the better condition the water is in, the more fish will thrive, hence grow. Also feeding them foods that are more from their natural environment (i.e. brine shrimp, bloodworms, etc etc etc) will promote breeding and rapid growth.
I do a 1/3 water change on my 55 gal
freshwater tank and my 2 bala sharks and raphael have grown very very quickly!!! I only feed them flakes and "tropical crumbles" which reminds me Im almost out
46 Gallon Bow F/W: 4 - Zebra Danio's, 2 - Red Platy's, 2 - lg. Silver Dollars, 1 - Pleco (4.5"), 1- Gourami, 1 - Cory Cat, 1 - mystery snail, 4 - Cherry Barbs, 1 - Black Molly