The tank is well covered, and the only other inhabitants, other than what's growing in/on the liverock is 2 tiny blue leg hermits, a tiny purple crab (filter feeder, about the size of a dime), and a small margarita snail. I do frequent water changes. I wanted 1 really small fish, and my fiance doesn't care for the neon gobies, but she likes this, if I can find one (they're probably $100, which will kill the whole plan).