Why process of growing small discus fish is different? I have about 25pcs of young fishes and some of them is 2cm and another 5 cm. What is the reason of this size? They have been born in the same day.
To get all fries to grow in the same size is an art in feeding.
You have 25 pieces of discus fishes. You will know how much exactly they can eat. Feed them heavily at a time. They need not fight but they have their share. Even the weaker ones also have taken their share.
After half an hour or so, siphon the entire left-over, so as not to pollute the water.
Of cause you have to keep the fish healthy. They should not fall sick.