Inches hps lights should be above colas

[chuckler]

What's the ideal height lights should be above the colas?

Thanks in advance.

 

[Kushwick]

If its air cooled I like to keep it 6-8 inches if not depending on wattage it would be anywhere from 8 to 24 inches.

 

[baba G]

non air cooled 1kw, I prefer 30-36". def 3 feet by the end...

 

[chuckler]

I have aircooled HPS lights...but 6"-8" seems pretty close but I am relying on you guys with experience. Any other opinions?

 

[justhydronow]

about 2-2.5 feet.

 

[ttystikk]

I have aircooled HPS lights...but 6"-8" seems pretty close but I am relying on you guys with experience. Any other opinions?

Brand matters. If you're running xxxl magnums or similar, you can get the hood closer to the plants without burning. Radiant hoods have hotspots that prevent this.

Just because you CAN get away with being this close in no way means it's desirable. A thouie in a good hood should be 24-36" from the plants. Bare thouie 18"-30".

It's a common newbie mistake to let plants get too close to the bulb. In addition to hurting quality, it also shades the rest of the plant, hurting yield.

 

[sixstring]

this chart has been floating around the net for a minute. kinda cool to see how quick the lumens drop off as you back off the light.

I run cooltubes and movers and keep my lights (600 hps) about 4-6 inches from the tops.10-12" for the non mover tubes

 

[chuckler]

Great chart! That's just what the doctor ordered along with the other good feedback.