As I'am sitting here enjoying my 29 gallon with two Amphiprion occelaris clownfish and my two clown gobies. is there any more room for a fish who swims out in the open most of the day, my clownfish seem to poke there heads out between the rocks once in a while and my clown gobies are always on the sand swimming around and i can see them more than the clownfish, so here is my question...Do i have room for anymore fish ideally one that swims around int he open water of my tank? i would love a tang, but i know tangs need at least 80 gallons of water and a tank with a reasonbly length. is there a fish?