yes! I have 8 - 48" T5s running on dual icecap 660s over one side of my frag tank.....SPS is looking very good!
Icecap says that each bulb is getting about 83 watts each......but make sure to get good bulbs......the crappy ones burn crazy colors when you over drive them! The giessemann bulbs are working very well for me!
heat is not a big deal, though the bulbs do get hot! just a small fan or two blowing over the bulbs is good! and make sure to get top of the line reflectors for your T5s
the actinic plus bulbs are about the same color as the radium 20K bulbs! keep that in mind! You'll get much better color if you use actinic plus, aquablue and pure actinic bulbs that if you try to use some 10Ks to get better par and supplement them with actinics
I already made the mistake of putting the lights too close to the coral.....the T5s are bright!