I currently have a yellow watchman goby and a firefish (and 2 false perc clowns) in a 29g biocube. I was thinking of getting a neon goby or blue grudgeon dartfish, but I know some gobies don't get along-would he work with the YWG and firefish? I'm looking to add one more fish and would like it to be blue. Trying to keep my peaceful tank! If the neon goby can't work, what about a Starcki damsel or a cherub angelfish? Or any other suggestions for a swimming fish (preferably with blue and not aggressive)