THE 430 CAN SAFELY HANDLE ONLY TWO 4' T'5S, period or KABOOM.
Ok, the caps are off now, sorry about that, but i BLOW up my Icecap by putting three 4'ers on it. I talked to tech support and after researching, that is what they told me. Of course, i had to have mine rebuilt.
The 430 will overdrive the 4' 55 watt bulbs to around 80 watts per Andy@Icecap.
If you have any questions about using T5's, then call Icecap first, they will tell you if it can work or not.