Depends on how many aquarays you have. I kept a haddoni and a magnifica under TMC tiles for about a year. The haddoni was (obviously) on the sand under 24" of water and the mag was under about 8" of water. The colour of the haddoni dulled slightly but otherwise it remained healthy and didn't bleach. The mag remained the same. So, in short, yes you can BUT just as with any other type of lighting you must provide enough. FWIW I had eight of the marine white 1000HD tiles over the tank which is 52" long x 32" wide. Giganteas are notoriously poor shippers but if you can get them over the initial acclimatisation phase which is when most losses occur, then they are fairly hardy but do require decent flow and ahem, lighting.