I have a 30 gal setup and it's been running for a year. I am looking to add some color. I have T5 lighting. What type of coral would multiply and spread the quickest? Looking at SPS, LPS and mushroom. Open to any ideas.
Personally I'd upgrade or add some additional lighting before doing coral, 2 tubes isn't enough for any SPS, and rather limiting on everything else as well. You should be able to do the standard little mushrooms, zoa's, and some polyp's. for LPS MAYBE tube coral and duncan's.
But if I was you I'd supplement the lighting with 2 more tubes or an LED strip like Current marine orbit.