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H.P.S. Lighting Distances

Posted: Sat Oct 04, 2014 2:54 am
by TokenTray
I am new to growing Indoors with Lights. I have a 4 foot deep and 6 feet wide grow room. I am using a 400 watt H.P.S. bulb under one of my lamp hoods and under the other lamp hood I have a 250 watt H.P.S. bulb and two 150 watt H.P.S. bulbs. I currently have the lights approx. 18-20 inches from the plants. I have not found any info. on what distance the H.P.S. bulbs should be kept from the plants. All pictures that I have seen on grow room setups the lights appear to be a much greater distance from the plants than where mine are set at. Please point me in the right direction on some reading material

Re: H.P.S. Lighting Distances

Posted: Wed Oct 08, 2014 12:11 pm
by TokenTray
30-50cm for a 400w HPS
50-80cm for a 600w HPS
the best way to make sure a plant is happy imo is to use the back of your hand, hold the back of your and at the top of your plant/plants, if your hand burns or starts geting warmer and warmer you know your light is too close, if you can leave the back of your hand under the light without getting a heat increase you know the light is at a good height.