What does Barnacles eat? In fact, barnacles are the organisms-filtrates. Organisms-filtrates feed on suspended particles of food, which they catch from the water. That is why, as already mentioned above, barnacles are excellent filters that help to purify water. Barnacles can be fed with finely divided feed particles for aquarium fish.
Barnacles are peaceful creatures that will never harm aquarium fish or other invertebrates. Under normal conditions, aquarium fish can not harm barnacles because of their strong shells. However, it is better not to place barnacles in one aquarium with large carnivorous aquarium fish, which can injure them or even eat them. Barnacles should not be kept in the aquarium during its treatment with antibiotics.