~INFO~
I have an 8ft room to play around with....and would like a style that gives me more yield right now i get 6 plants every 2 weeks and i have 3 stages under the 400 watt. I have a fourth stage for the first 2 weeks for flowering under 6-T12 bulbs.

im thinking of making a tent out of mylar to hang around the 400watt in a cone type shape and putting a box fan in the side to vent the air. about a 4ft area approximately under the 400watt. I thought of hanging a box fan directly unde a side of the light below the reflector to keep the stuff cooler. thought of framing it with wire as well..... any thoughts on this?

so why is it that the 400 watter needs to be separated from the rest? can you provide a picture? if i'm reading you right, you have 4 different stages of flowering in this, 3 of which are under the HPS, and the other is under some T-12's, right? Why don't you just upgrade to a 600 watt and have all 4 stages under the same light?

__________________
"Enlighten the people generally, and tyranny and oppressions of body and mind will vanish like evil spirits at the dawn of day." - Thomas Jefferson

"Every generation needs a new revolution." - Thomas Jefferson

Heat rises. Chimneys vent out the top not the side. Box fans aren't suited to this use. VV

i do believe that a box fan hanging directly from the reflector on the highest setting should be fine enough to suck all the air away from that light. i planned on leaving a airspace around it to pull air in and over the light down the curtain and through the fan. not all light have to have a cooltube to vent them.

im happy with the yield of the 400 i use. I want to use all the light that my light gives me because a LOT of it is lost because of distance. a mylar tent would prevent that.
my garden in a sog prepetual style. all of it is in soil pots right next to another. the diffrent stages are actuall just plants in diffrent stages of flowering.
the ones under the fluros are just vegging a tad bit after rooting to make them good and healthy.

it seems that for the amount of trouble you would have to go through to make this happen, you could just as easily build a cooltube in order to get your light closer to your plants and provide better light penetration.

how are you planning on ventilating this mylar tent? the air will need to be exchanged in some way, because blowing hot air around will do nothing for your situation.

__________________
"Enlighten the people generally, and tyranny and oppressions of body and mind will vanish like evil spirits at the dawn of day." - Thomas Jefferson

"Every generation needs a new revolution." - Thomas Jefferson

Well first off, what is the total size of the room?

H x W x L ?

Can you do construction in the room?

What's the preferred medium?

Budget?

You are right of course, I don't have a cool tube on any of my lights. And if I wanted to I could ghetto rig a box fan to move air around the room. I thought you were looking for advice. I guess if you wanted an opinion you would give it to us. That doesn't mean I don't like you... yet. VV

im not trying to be a smart ass,
but i dont care if you hate me either.as far as im concerned i could be osama's momma to ya.
i want to know if a mylar tent around a 3-4ft area will help contain the light that escapes to become SUPPLAMENTAL light instead of light that i can use.
I know the box fan would vent that. Thats all i was trying to tell ya holmes. now if YOU cant vent a 400 with a box fan there is a PROBLEM. the bulb only makes about 20 degrees of heat that id have to vent.