It all depends on whom you are feeding and what you are feeding. Feeding hearty eaters (like my livebearers) tropical flakes for 3 minutes seems a recipe for disaster, but they do need that time to tackle a pea. And my corys often need 3 minutes to work out that dinner is served. So I think the answer is - stick to what you are doing, you're clearly doing it right. I feed a set amount of not more than 3 flakes a day/fish.