I tried shooting a tank lit by leds, and it was not fun what so ever, pretty much my nikon d700 couldn't handle the blues. Zero definition, but push your white balance to the sky14,000k (if you can go that high). Shoot and try to find contrast (example the guys yellow tang came out sweet), then if you have lightroom play with the white balance and tint way green. That should help.
If you need info on your camera, youtube will teach you your settings, and if yiu want other awesome help the scott kelby dsl how to bokks are awesome.