New MH/HPS Light Position!?

So, I just bit the bullet and bough a new 400W MH/HPS ballast and a reflector...

My Grow area is nearly 5' tall, and 3x3' at the floor...surrounded in mylar... I have 6 plants... if you subtract the space required by the new reflector it gives me 4'1" of vertical space until you start touching the bottom of the reflector...

My question is, should I just screw making it adjustable and mount it up as far as I can get it, or make it adjustable...? the MH bulb I got for vegging makes about 30,000 lumens and the HPS bulb for flowering is 55,000... Will enough light make it the 4' to the ground to be as effective as it could be?


Thanks...

make it adjustable, same set up i started with, i flower at 14-18 inches, and bring it up as they come up, by the time there done, the light is at its highest, i started the box at 48 inches and had to go up 12 inches more, so i'm at 5 now and its perfect, now i got a 1000 watt going in ina week, cuz the tops do great, its the bottoms that kinda suffer, but i also do 10-12 under the 400, i know its too many, but thats what i get stuck with, but if your only doing 6 should be good.

When your plants were seedlings how far away was the light? 12"?

i do clones, never did seeds but i'm growning a strain that stretches very easily, 12 is good, start, keep yer eye on it, i've had my 400 6 inches away without any probs

I was running CFLs so it's all new to me... You run your lights 24 hours during veg or do 18/6?

If you have mylar or another good reflective coating on the walls it will not make much difference how high the light is. I would put it up top and leave it there.

Here it is all mounted up... it's about 6" above where it will be... I did make it adjustable... my light meter shows a loss of about 500 footcandles for every 12" it goes up with the meter in a position where a seedling would be...

What do you think?

looks good, i would put a fan blowing on the light to keep the temps down in the shroud, i think mylar is way over rated and expensive, white semi or gloss paint works great, i use the back side of wrapping paper glued to cardboard works jsut as good as any mylar i have used

Yeah actually there are a couple fans blowing up on the light... I just didn't have them in the pic The light with the fans blowing on it at the position you see it in the pics is pretty steady at about 91F... so I guess I'm going have to bring them up...

And for clarification, that temp is measured by a thermometer sitting at future plant level...

thats hot, you need to get temps down, are the ends of that shroud open?

cloneup said:

thats hot, you need to get temps down, are the ends of that shroud open?

Click to expand...

i just looked back at the pics and answered my own question, run your duct right under your socket, and take the other end of the shroud off so the heat blows out, its not going to make a big difference on losing light as it is getting rid of heat outta the shroud.