Lux, Lumens, PAR, Wattage and whatever else you want to call lighting ....

Ok folks, I have read so much that my eyes feel like they are going to bleed. There is a very nice thread in the indoor grow section that is stickied, but even it doesn't break it down to the "Lighting for Dummies" level.

That being said, I want the answer to a simple question. Using HPS lighting, how many watts per square feet is optimal?

I have seen answers on this forum and others that go as low as 20 watts per square foot and up. Since infinite is not the right answer (even if it is, which I doubt) what is the optimum wattage per square foot?

Anyone want to step up to the plate and throw a number out there? Preferably one with some thought behind it. Thanks.

Bumping this thread with a url that may be interesting to new growers. Go here: http://www.cannastats.com/yor/lighttabwpsf.htm for a nice breakdown of lumens per square foot, approximate wattage, and the "sweet spot" determined by polling growers over a period of years.

Many thanks to Brick Top who provided me with this link. Much thanks to him and the other veteran growers who have been kind enough to help me out.

I would 50W does the trick.

Oh, and based on this lighting breakdown, I decided that I am going to go with a minimum of 8000 lumens per square foot to cover a 10' X 10' grow area.

To get my feet wet first though, and iron out any potential problems, I plan on doing an initial grow in about half my total grow space with two rows of three 600W lights. This will have a side benefit of temporarily pushing my lumens to square foot up to about 10,500:1, which is a nice ratio.

Currently planning on using Hortilux Eye brand 600W light bulbs (again, thanks to another veteran poster, subcool). No real idea on what these bulbs PAR rating would be, but as they are an industry leading grow bulb, it should do fine.