Tetramin Tropical Flakes Ingredients:
Fish Meal, Dried Yeast, Ground Brown Rice, Shrimp Meal, Wheat Gluten, Feeding Oat Meal, Fish Oil, Potato Protein, Dehulled Soybean Meal, Soybean Oil, Algae Meal, Sorbitol, Lecithin, Monobasic Calcium Phosphate, Ascorbic Acid (source of Vitamin C), Yeast Extract, Inositol, Niacin, L-Ascorbyl-2-Polyphosphate ...
I don't consider any fish food with the main ingredient of fish meal to be high quality!!!
Unfortunately, most fish meal is low quality (ground heads, scales, bones) - cannery byproducts of parts of fish that can't be used for any other purpose, let alone human consumption. It's ground, dried, loaded with preservative, and sits in a warehouse for extended periods before ordered by a fish food manufacturer. As a dry powder, (rather than a wet protein) it requires copious amounts of (grain) starch as binder/filler (notice the rice, wheat gluten, and oat meal).
Fish don't handle grains well so this means a lot more fish waste as it just passes through!
The high quality fish foods have a main ingredient of whole fish!
I feed mostly Omega One Tropical Flakes with some New Life Spectrum tossed in.
Omega One Ingredients:
Whole Salmon, Halibut, Black Cod, Whole Herring , Whole Shrimp, Whole Krill, Wheat Flour, Wheat Gluten, Fresh Kelp, Lecithin, Astaxanthin, L-Ascorbyl-2-Phosphate (Source Of Vitamin C), Natural And Artificial Colors, Vitamin A Acetate, Vitamin D3 Supplement, Vitamin E Supplement, Vitamin B12 Supplement, Riboflavin,
(Note: I have no affiliation with any fish food manufacturer.)
To the question of feeding, it really varies. If they were in the wild, fish would be hunting for food most of the daylight hours, but success rates would vary.
In general I'd say to feed once or twice a day in small amounts. But there are exceptions...
My 60g has turned into a grow out tank for dozens of growing fry (I became an 'accidental breeder!). I have two Eheim Everyday Feeders setup and feed the fish small amounts roughly every 2 hours during the day!