hor far away your plants should be from your lights

depending on what size and kind of lights we are using.i am going to start with the vegetative lights first.i use a 2ft. by 4ft 8 tube t5 fixture.i like to keep my light about 4 inches above my plants.your nodes on the plant will be real close together and that means more branches on your plants.which equals more medicine for you!if you are using a 400 watt metal halide you should keep your light at least 6 inches away from the top of the plants the same can be said for 600 watt lights as well.now if you are using a 1000 watt metal halide you need to be 12 inches to 18 inches away from the top of your plants. now with that being said the type of hood you use will also play a factor in how close you can be to the top of your plant.i suggest you do not use or buy a parabolic hood.while they disperse light really well they act like a giant umbrella that traps all the heat near your plants.gull wing hoods work well and the price is right if working on a budget.i like to use the RAPTOR hood.it is air cooled with 8 inch flanges.this means i can put my 1000 watt light about 8 inches above my plants!there are other lights out there and they have smaller flanges that work well to.well i hope this has been helpful to somebody out there.you can leave comments or ask questions.as always check out the ads.i endorse these products.