I just did (same size tank). My bicolor is the most territorial fish in the tank - he doesn't like anyone on "his" rocks, but ignores the sandbed. So hopefully they get along... so far, I haven't even seen the diamond goby since putting him in the tank though! I think he's dug out a cave behind the rocks. The only evidence he's still alive is the pile of sand he spit to the side of the tank, lol. Hoping he'll come out more when he's settled in.Could I add any of those Goby along with a Bicolor Blenny? 33 gallon (125L) display.