600w HPS height above plants?

cory9oh4

Member

  • So...

    I have 6 "tomato" plants growing under my 600w hps. Some of the leaf tips were starting to burn which suggests my light is to close. It was about 13" from the top of the closest cola.

    Question is:
    How far should the light be away?

    Also, I have 1x 2300k 300w CFL & 3x 5600k 100w CFL spread around the plants to hit lower foliage and buds.​


 

thc&me

Active Member
Wow. You've got tomato plants with Colas? But seriously, burnt leaf tips are usually associated with over-fertilization. Cut back on the nutrients at feeding and they'll be fine. If it gets worse, consider flushing the soil with straight H2O. I think your lights are fine at that distance. Put your hand under the lamp at canopy level. If it's uncomfortable, then they're too close. If it feels only mildly warm, then you're golden.
 

sfttailpaul

Active Member
Man oh man, what strain of Tomatoe are you growing/ I've heard of grafting the Hops plant on to the root system of a Marijuana plant, producing a vine that looks like Hops and the genetics of Marijuana actually growing. Doesn't work at all. So I'd be interested in a Tomatoe version. Great stealth grow; could plant out behind the police station...Best test of "How high above the tops should my 600W light bulb be at" would be to hold your hand there and wait a few minutes to feel the heat. If your hand can tolerate , it is fine; if you feel too much, raise the fixture. I have 600W HPS on light movers so I can actually go lower than a stationary reflector and I am at last 18" above, so I'd venture to say that you are too low.
 

ShLUbY

Well-Known Member
leaf tips burning is nut burn... if your light is too low your plants leaves will actually droop down away from the light... above poster mentioned the correct method (as there is no "correct" height because it depends on your light system) just place your hand under the light where your highest cola is... if its uncomfortable to keep your hand there then raise it.. another good way to check is just take the temp measuring end from your thermostat and tie it to the top cola... that should tell you exactly what you need to do... anything over 80 is unacceptable unless your supplementing your room with lots of co2
 
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