I just started a 30 gal saltwater aquarium and have under-gravel, canaster and protien skimmer with bio material. I have 6 fish (2 clowns, 2 yellow tail damsels and 2 blue damsels.) Its a new tank and I dont expect the protien skimmer to pick up much...but when it did it flooded the catch container. It also changes every time i feed the fish or add anything to the water like amonia clear. does anyone know if this is normal or should i look for another skimmer.