Your mollies are going to want a
herbivore food, at least some of the time. The other fish, I believe, will do well with a more general fish food. All of their diets should be supplemented by treats of things like blood worms, fresh veggies, or whatever.
Things to avoid: Cheap food that has "meal" in the name. The number one brand to avoid is Tetra.
The reason for this is that "meal" is often the waste parts of a product. Thus, fish meal is often the bones and skin of a fish. Corn meal is often corn minus the germ, which has a lot of the few vitamins that are in corn.
"Meal" can also be ground-up whole product, though. I have no confirmation on this, but I believe that this is what Hikari uses in their food, simply because it is the brand used by professional Japanese koi breeders.
Some brands, like OmegaOne, actually say "whole
krill" "whole salmon" in their products. These are the best, because they tell you exactly what you need to know. OmegaOne is the other brand that I go with for my fish.
A minimum of dyes and preservatives are good, too. This one takes a little bit of homework, because not all chemicals are preservatives. Some are important vitamins or mineral sources.
Thanks, sirdarksol! I've been giving them bloodworms and veggies on occasion, but I've been using Tetra flakes. I'll pick up a better brand next time I go to the store.
haha, JK