Just because the WH ballasts work with T5HO, and the tech claims (dubiously) that they were designed for T5HO, doesn't mean they'll perform as well as programmed start ballasts.
The WH ballasts are 'Instant On', meaning you get a large power spike whenever they fire the bulbs, which is what reduces lamp life.
WH ballasts are pretty much 'general purpose' ballasts, and from what I understand, back when T5HO lighting was first being adopted here in the States (and on this forum), Fulham didn't even have any information on their site whether or not their ballasts would work with T5HO... it took some experimentation from people in this forum to determine if in fact they would work.
So in this instance, I think the tech was pulling your leg... which isn't beyond reason, being that he's a Fulham employee and isn't going to tell a potential customer (or current customer) that they'd be better off buying a different brand ballast.
I recently purchased four 39w 36" T5HO (Sunlight Supply Tek 5) kits, which include Giesemann bulbs, Tek 5 reflectors, Waterproof endcaps/mounts, ballast (not sure which kind since I haven't gotten them yet), wire and power cord, from specialty-lights.com for $149 each with free shipping... I tried piecing together the kits myself from parts, but the closest I could get was about $130 before bulbs, plus shipping, so I opted to just get the kits, even though the Tek 5 reflectors aren't the best out there.
I'll assess the situation and possibly replace the reflectors in the future.
