I haven't had much luck with pellets or flakes. I find that they contain a lot of filler (wheat, brewer's yeast, soy) and some of the key ingredients (spirulina) are not very high on the ingredient list. Plus, some pellets/flakes contain nasty preservatives like Ethoxyquin (Omega One).

Even some of the best brands, like Hikari, have way too much filler.
The krill that we buy is a bit pricey but lasts for quite awhile. We buy the spirulina flakes in bulk and they are super cheap. The algae tablets are cheap too, just make sure they are high quality and fresh. Ours will not eat anything that isn't fresh.

You can also supplement with various veggies, like zucchini, spinach, peas.
