They are docile like a Clown Goby but they are smaller and more inclined to get by with less food. Do not use flaked food in this tank, it's not going to work that way. You're going to need to be careful that everything fed is eaten quickly and that the fish are not overfed. Your tolerances here are very tight and the slightest error will be magnified in such a small tank. Clown Gobies have a habit of watching food drop past them. Neons and Barnacle Blennies will not only grab food when it hits the water, they will also scavenge food from the substrate.