I'm about to start my first grow, have three 400w on the way (2hps & 1mh) and I'm just learning bout UV exposure. I'm starting with 8 plants, 2 Sour Diesel, 2 Citrus Diesel, 2 Blueberry, 1 Grape Ape, & 1 Oak Leaf.

I've read that UVA exposure is important as UVB rays use them somehow, but overexposure to UVA can be dangerous. I also heard that the reptile lights give off much more UVA than UVB.

That said, I'll probably start off with 2 reptile lamps due to cash flow problems. I'll start with one on each side of the 2 rows of plants. I'll hang them hi at first and I'll slowly move them closer to the plant till I'm as close as I can be, and I'm going to try using them during veg to see if it helps.

I'm going to be looking to upgrade as soon as I can. Very early in this thread someone mentioned that www.reptileuv.com was developing a UV Metal Halide, well it's here and they're selling them. I just wish I could read the charts. Can someone read them and let us all know how they stack up against the other types, and also let us know if it's overkill or if they just took regular MHs and renamed them.

Can you also break down the UVA & UVC levels in these UV MHs.

Thanks.

Attached Images

	UVB iso-irradiance Diagram.gif (41.7 KB, 8 views)
	UV Index iso-irradiance Diagram.gif (45.6 KB, 7 views)

Thats a good bulb if your plants are directly underneath it. It just doesn't have the width of light I would want. I plan on using the Mega-Ray 160w Narrow Flood lamp.

You can see how it performs here:

http://www.uvguide.co.uk/spreadchartcombo.htm

Almost 48 inch wingspan versus the 24 or so for the MH you posted.

That MH is also $120. At least it doesn't produce extra heat like the flood lamps though.

Thanks for the info, what a bummer though. I didn't see the pic with the spotlights and I was assuming that all metal halide bulbs were made in the same shape as a MH Grow light and use the same kind of ballast. I can't imagine why they wouldn't make them that way but I hope they start making them soon. Spotlights are going to be harder to work with, even the wide angle ones. Oh well, we can't have everything I guess.

Can anyone tell me how to figure out the UVA, UVB, & UVC output of a bulb. I guess I'm going to start with aquarium lamps and I want to buy the one with the lowest UVA output. Problem is these bulbs don't list a breakdown of the UV spectrums and in most cases don't even list the total UV output.