HPS question

hi there,im just about to set up my flowering area its 4x6x7ft i bought a 600w hps with isis reflector i have a 320cfm exhaust fan onto a carbon filter and fans inside that will blow over the canopy with passive intake.My q is what is the optimum distance the light should be from the canopy? i usually just go by the heat at the top of the canopy and look at the plant to see how it handles it.but ive always wondered what the "correct" distance is.Thanks for reading people

I keep my 1000 18 inches from my canopy and it works great...good luck

so if i keep my 600 12 inches that should be good?

my hps is about a foot away (maybe a little closer actually)and worked great for 3 of my girls.

As close as you can get it with no signs of burning. There really is no magic number.
It differs depending on fans and locations, cool tube, ambient temp etc.

Closetgardner said:

hi there,im just about to set up my flowering area its 4x6x7ft i bought a 600w hps with isis reflector i have a 320cfm exhaust fan onto a carbon filter and fans inside that will blow over the canopy with passive intake.My q is what is the optimum distance the light should be from the canopy? i usually just go by the heat at the top of the canopy and look at the plant to see how it handles it.but ive always wondered what the "correct" distance is.Thanks for reading people

Click to expand...

With a 600 watt hps it will cover an adequate area of 3 x 3 space. Is your model air cooled or is it an open fixture? If it is an open fixture then play around with the distance by placing your hand under bulb basically if your hand doesnt get hot then your canopy wont as well. Minimal requirements to flower in terms of lumens is 10,000. And with a 600 watter you can achieve that when your distance from your canopy is about 3 feet. However you want more lumens to bomb your plants to get bigger buds, therefore you decrease the distance of your bulb to your canopy. There isnt really a universal distance because you have to consider everyones grow is not identical and factors like if your hood can be air cooled, if you have adequate air flow, your actual ambient temperature, if your using a light mover and there are other factors to take under consideration as well.

I put my hand right above the plant if it feels like I would be uncomfortable I move it up until I am not.

Ask and ye shall receive.

View attachment 2281671

That graph doesn't factor in heat.

"I put my hand right above the plant if it feels like I would be uncomfortable I move it up until I am not."

Nailed it. I call it doing the hand test.

BigSteve.

thanks everyone

i dont know how to use the multi quote so

calicat-no the hood is an open fixture one........thanks to everyone else the "hand test" is the way i usually do it.

Keep a fan moving across the canopy, it'll help you get a bit closer