t5 ballasts
 

so..theoretically speaking a workhorse 7 maxes at 220w which means i could run 4x54w HO t5s? do t5s match vhos for output?

I'm running 2x21W and 2x39W T5s off a WH7 (the NO tubes are because I can't get at HO blues for a price I won't balk at). I upgraded the NO whites to HO a couple weeks ago and swapped one at a time to see if it's actually driving bulbs correctly... WOW! It sure worked, and these suckers are bright. With parabolic reflectors I'd say the T5s rival VHOs easily. I was seeing stars for minutes after I put everything back in place and walked away.