I'm a firm believer in you get what you pay for in quality of food.
Same here! Who says I don't buy high quality foods though? 90% of fish is all genetics trust me I been feeding my fish variety of foods from hikari, new spectrum, shrimp pellets to you name it and they all do the same damn thing. The fish food I buy is made for koi and has the best ingredients in it. Better than the brands listed. Whole fish meal with krill meal and many more including asathaxin for coloring.
A good protein content and a variety of diet is all you need. Been doing this for 15 years and never let me down. Always have a ton of growth and my fish breed frequently without me even trying.
This guy uses the same thing.