There are three types of pellets available in the stores: floating pellets, slow-sinking pellets, and fast-sinking pellets. Pellets result much better as a food source when it comes to big fishes. However, some small fishes like betas can eat them as well. There are types of pellets that float and other types that sink very quickly.
As we explained before, flakes don’t last long once you have opened them, on the contrary, pellets have a longer shelf life, and therefore you can save money with pellets in the long term. Notwithstanding, as it happens with flakes, pellets have also some cons to bear in mind when choosing the proper food for your fishes. The type of pellets that sink immediately can sit at the tank bottom and rot, which will raise the levels of ammonia in the water, polluting it dangerously. Also, some types of bottom fishes can confuse pellets with gravel, finally eating them. In conclusion, both flakes and pellets have upsides and downsides, and the reasons for choosing one type of food will also depend on the types of fishes that you have, and therefore their specific needs.