Hmm, looks like actually I could probably get 175 watt SE ballasts for about $130, lamp holders for $30 each. So, yeah, $160 not including the bulb. I wouldn't think heat would be too bad, there are heaps of retrofit kits designed for exactly the same thing. I asked about them at redwoods...$1700 for one that bad been used in the shop.
I suppose a single 175 would end up with just the center of the tank being lit, but would cut any heat concerns in half. But, you think it'd be more light than I'd need, Pies?
I've had a closer look at how much space I have and if I transferred the 4' T8s into the hood they'd be practically touching, what effect would that have on lighting efficiency?
Just seems that still the MHs might be the easiest, most effective, and not too expensive.