Im wondering if ppl can give me some advice on fish compatibility. i'm looking at purchasing a pair of Sleeper Gobys (not sure of the scientific name, but its not the yellowheaded sleeper goby, they have a white body). Currently in the tank is a pair of clowns, a yellow tang, a mandarin fish, 2 large cleaner shrimp and a lawnmower blenny. Tank is 400L, with liverock and sandbed around 5cm thick. i'm wondering about the compatibility of the gobies with the lawnmower blenny, is their likely to be aggression, the only info i could find is that lawnmower blennies usually only become aggressive to other algae eaters. I have quite a lot of diatom growth on my sand and the gobies appeal because of their sand sifting behaviour. The pair that i'm looking at apparently are eating pellets and mysid shrimp.
So any thoughts ppl?