Stocking

[Nrm]

Hello! I have a 20 gallon long with 2 clowns, a yellow clown goby, cuc, and a cleaner shrimp. Is there one more fish I could do that anyone recommends? I also have a 24 cube with a pistol/watchman, royal gramma, and possum wrasse etc.
I would prefer the last guy for the 20 to be different than everything else. Any recommendations?

 

[TX_REEF]

I wouldn't add another goby, seems likely to result in violence in a tank that size. Royal gramma might work out, but still a risk given tank size.

 

[Mr. Mojo Rising]

A tailspot blenny would be a great addition IMO