[Delphinus]

So run the 400 at 20k and the 175s at 10k. Would that be a good combo? Would i still need actinics or would this be ok on it's own? The reason i didn't really want to do it this way was the heat issue, also electricity cost. I worked it out the cost should only be $3-4 more a month so big deal, just the heat. Any other draw backs?

Just the heat, and that will be a very serious concern in an enclosed hood (aka heat trap). But some fans will solve that pretty easily.

As for the lighting combo, I think it would be one of the best combos you can get. You wouldn't need actinics unless you wanted them there.

yah but can you afford to replace the bulbs every year. A 400w 20k bulb costs over $250 and 175w 10k bulbs are $200 a piece.

Well the bulb cost will be concern, true, but if you're paying $200 for a 10kK bulb you're paying too much by a factor of at least 2. MO prices are in the $100 range, and can be even less if you wait out for the sales (I think I paid $90ea for mine).

Yeah, it's an expensive hobby... (Why didn't somebody say so before!!!!!) :D

But let me just say this. If a person is not sure they can afford to replace the bulbs on a yearly basis, or pay the electricity bill, then shouldn't that pretty much be the deciding factor? I offer my suggestions as just that ... suggestions "to be taken under advisement." Only you can decide what's right for yourself! If you can afford it, great; if not, well hopefully something else will work out then (and there is always something else if you're creative, and take the time to understand the how's and why's).

PS. I have no idea how often a 20k bulb needs replacing. My first halides were those 14kK's or 12kK's or something and I found they were useless after 8 months. After 8 months the only things that grew while under those lights were hair algae and cyano... so there is that as food for thought...