I have both cleaner and peppermint shrimp in both my systems, 210 and 75. Each has 4 cleaners and a dozen peppermint. Cleaner shrimp try to steal food from the anemones if I feed them. I have caught the peppermint shrimp making a meal out of my gigs at night, they only make an appearance at night. They will sit and pick chunks off of a normally healthy anemone and enjoy. Doesn't seem to affect the anemones, but they are established and healthy anemones. Cleaner shrimp seem to only go after food, peppermints go after food and anemone. Cleaner shrimp can go digging inside the anemone, potentially internally injuring it. Otherwise cleaners seem harmless.