A balanced diet for your aquarium fish is essential to thier survival. Most of the commercially available dry fish foods are almost always unbalanced. In many cases, the vitamin content will gradually decline at room temperature and since majority of the dry food for tropical fish commonly used will only keep for about three months, it is always advisable to buy fish-feeds in many small packs rather than in one large pack.
The feed could preferably be kept absolutely dry in a refrigerator. However, all fish appreciate a change of diet and will thank you for your consideration with more interesting behavior, better colours, and greater readiness to breed and better general well -being. This change of diet should be supplemented with live food; majority of which now come in irradiated freeze dried forms to make sure that they are disease free.
I will mention a few that could be found handy in some major aquarium shops and I will group them into two. And they are flake foods and freeze-dried foods
Flake foods
Most popular and highly recommended brands are Aquarian