I just installed my screen. I currently have 23" between the screen and the glass panel of my 400w HPS. I can only raise the light another inch, which I will do when needed. I can only lower the screen 2 more inches at most, but that would make working underneath of it kinda tough, especially since this will be my first scrog. But if I have to, I have to. I am growing one White Widow, and one Northern Light. They are about 2 inches from reaching the screen. They will be 28 days old on Monday. So will 23" inches be enough, or should I try and capture that remaining 3 inches I can achieve, so for that matter, will 26" be enough grow height, because if not, then I am truly screwed. lol. Thanks. Peace.
whats the over all hight of the space? i keep my light about 18 inches above plants. i'm using buckets and my screen is 10" above the bucket tops. then i let my girls grow and keep them under the screen for the first 2 weeks of 12/12 and then let them go. they slow down growing after 3 weeks. you don't want alot of the plant above the screen just the bud sites. idealy just about 3 or 4 inches of plant above the screen so when they really flower the light is focused on the buds. less wastage.
The overall height in my grow tent is 5'3". But with my 18 Gal Rubbermaid Res, and my 400W HPS light, that takes a lot of the space away. But anyway, like I said, I currently have 23". My only concern is if that's enough space after the vegging is over, and the flowering begins. Basically I am asking if the bud sites coming up through the screen will get to 23" long or not. I guess if you are 18" away, then 23 is good then?
Yeah, 23" should be good. With the reflector being air cooled you should be able to grow right up to a few inches away from it. This gives you 18" or so of really good growing space. A 400w HPS maximizes its casting distance at 28" from the bulb, anything further than that won't recieve enough light energy (PAR) to allow for photosynthesis. So, once your canopy is filled in above the screen you are going to want to remove all the greenage (leaf mass) below the screen. This will increase air flow and remove the stuff that will only die off because it's not getting enough light. I like to keep my 400w HPS in a cool tube about 8" from the canopy at all times. I've gotten REALLY close before though (height problem, run away plants) and at around 4" or so you're going to get some light/lumen burn. I think you'll be alright though.
Thanks. Forgot to mention an important factor. My light is not air cooled. Its an old light. 16 year old Hydrofarm unit. New bulb. Currently tent temps are good with my exhaust, but I may have to install a flange to my light, and add some ducting to it to cool it as much as possible just because the buds will get close. And just for the record. My light is not 23" away, I am adjusting my light as the plants grow. Its about 15" away from the plants currently. 23 is just the number of inches I have to work with once the plants come through the screen, up to the maximum height of my light.
I'm guessing I had more room than that on my last grow and my super lemon haze was up against the light when I was done, but the critical mass was still well below it, so it depends on what your growing. lf its sativa, you probably don't have enough room I'd bet, but indica you should be ok
Thanks for that, but I was not asking about distance from light to plant, but rather total height available for the grow. More specifically, would that much room mean my buds would end up growing into my light. But I have also taken care of that by scrogging my grow, or attempting it anyway.