I have a cleaner shrimp, 8 bluelegged hermit crabs, 1 scarlet hermit, 4 small turbo snails, 2 zebra ceriths. I did not use RO water this water change cause i ran out but i think that is the reason cause last time i did the water change i didn't get brown algae and this time i used regular water, but i used that dechlorinator stuff. So i don't know.