I currently have a sleeper banded goby.. this little guy is busy all day sifting sand.. on the downside, I always have sand floating in the water column... these gobys do need a mature sandbed though...
I used a semi gloss latex. At first I tried to brush it on.. didn't work so well. the brush strokes really stood out.. Then used a roller and it worked good.. Also best to have the surface to be painted laying horizontal... otherwise the paint will run and separate leaving cracks.
I also have a 125 gal. and run 4 max-jet 1200, 2 on each end. I also have found that the best way for me to keep the phosphates in control is to run a phosban reactor.. using 150 mg of media that I change once a month.