Back in the day, live foods were really important as commercial foods were of questionable quality. However, today, there are some commercial foods even better than live foods....
Check the ingredient list on your fish food. Many, if not most, will begin with some type of grain (rice, oat, wheat gluten) that serves as the protein binder in the production process. This is often followed by fishmeal. The trouble with fishmeal is that it is typically waste products form canneries, ground, dried, and stored in a warehouse for an indeterminate amount of time until an order is placed by a fish food manufacturer. Check the ingredient list for products like Omega One and Almost Natural and you'll see that it begins with FISH as the primary ingredient, NOT grain. This matters because fish don't eat grain, can't process it, and it just passes through as waste. Way back when I switched to the high quality foods, I noticed far less fish waste! = healthier fish with less bio-load!
The high quality foods are also supplemented with vitamins and minerals you won't find in even a blend of live foods.
So use live (or frozen) foods as treats, but rely on the high quality commercial foods for well rounded nutrition.