Newbe questrion about lighting

I have a 1000 watt hps How close can I put it to the plants

Your reflector will influence that somewhat as it dictates the coverage area to a great degree and a good rule is no closer than is comfortable to your hand. Opinions vary of course but I understand "optimal" to be about 10", a 140K lumen bulb will provide 64K foot candles at that distance. Of course more details will get a more detailed answer, hope that helps.

10 inch's I will have to see how that feels... one person told me two feet lol

As close as you can get them without hurting the plant. The more light the better. Pay attention to the top leaves. If you see em start to curl along the edges, back em off. Do you have air cooled lights?

That could be true, part of that is the reflector but with a good air cooled tube or sealed hood it should be alright. I use my wrist (like checking a baby bottle) under the light to test the heat.

its not air cooled but I had the light about 15 inchs and some of the leaves started to curl up so I guess I should back them off a bit then

Air cooled hoods are more critical with lower wattage bulbs because of their decreased casting distance.

The same 140,000 lumen bulb would have up to 36 inches before the lumen level dips below 5,000 and you start seeing really decreased growth. So long as your entire plant (or the important parts at the least) are in that 10 inches to 36 inches window then you're going to be in good shape.

I'm not saying put your bulb 36 inches above. If you have 2 foot tall plants you could concentrate on the upper foot of them by keeping the light about 20" above the canopy. As with any light, and it almost goes without saying but... The closer you can get it the better. The money spent on a hood and a cooling system is necessary to really make full use of that lamp and its energy when it comes to harvest time.

I can't seem to keep track of where I find things but I ran across this chart on a forum somewhere, full credit to the original poster "CaliGrower". This doesn't consider heat or reflector/hood effects on coverage. This illustrates what Snow Crash was saying also.

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