Air cooled hood distance.

[DrPhoton]

How low can you have your air cooled hood ?. I have seen people state they have their hoods as low as 3-4 inches with good airflow. Typically though 10-15" is the average with 600 watt systems.

[oldjarhead100]

Danofdanger I run a 1000w hps never paid much attention to how far away it was.then I read Nebulas tutorial on Light bought a light meter and discovered that I was giving my plants way to much light. So now I raise or lower my light to give the BEST light to my plants .if I have a bud thats getting more than 85,000 lux then I either turn the plant or if more than one bud it getting to much light I raise the light until the lux falls into range. Has made a huge difference

[DrPhoton]

Thanks for the advice. I have ordered a lux meter in the end even after reaearching all i could. Theres too many variables to know to get a accurate judgement. Hood type, reflector material, lamp efficieny, power usage. Its all trial and error with each individuals setup, even the hand test is only for heat. Lux meter is really the only way for absolute accuracy.

[Potted]

It all depends on the temp. After all if light is to close it will burn the plants,with or without good air flow,I ajust light to best temp. I prefer the temp.about 77 deg.from top of plant just my .02$

[Marley]

I can't imagine 3-4 inches above the plant, even with good airflow, wouldn't light burn the plants.

You have to think about spread too, so even if you can get it lower it might not be getting as much light to the whole plant. I'd rather get a little less intensity on the tallest part of the plant if it means getting more light to the rest of the plant. But that's just me.