I'm still newish to sw
but I personally wouldn't put more than 1 more fish in there, since its 24 gallons. The fish you have now get to a good size for a 24g IMO
, so maybe 1 more small fish will stock the tank. Either the Neon Goby or the Firefish would be a good choice. I've been told that a single firefish sometimes shys away...so maybe the Neon Goby would be a better choice. I haven't kept one of those, so I'm not sure how they act. You could do the Royal Gramma instead of the Goby too, if you like them.....it would add some nice color. I'm sure other people will chime in.
edit: I changed the name of your thread so it would draw more people in.