grow temp prob

my grow room heats up to 90 if i do not leave door open , iam losen too much light or is this ok ?

A picture of the grow room or what light are u using. I use a 600hps in a 2'6"(2)x6' and I am at 85'. If you have mylar coated walls you will lose a little light down low. What is your humidity and what is your night time temps.

It all depends on how much light you are giving the plants in the first place... I'm running three 250W HPS, and a 400W MH in a 4' X 2' closet, with a box fan at the bottom, blowing up, a Vornado room circulator blowing up, and an oscil fan to dance my canopy around, not to mention I keep a fan on my remote ballasts in the room outside the closet, which blows that hot air out of the whole room, and I leave my grow door open, but I do use a thick, white towel to not only reflect back, but also to allow for plenty of ventilation, as well as a "barrier" to keep in some of the CO2 I produce as well, and I run 73-80 degrees from night to peak daytime temp, and at the hottest, my plants are as healthy and lush and during flowering, are always just covered in trich's and as sticky as you please... So, yes, and no-it just depends... 90 is REALLY a little bit too hot though, I'm fairly sure.... Not saying it's not do-able, but I'd be getting a bit worried at those temps, myself... I'd leave it open if you can, without having any security issues...

What are you going to do when you flip to 12/12??? Obviously you can't leave the door open. What kind of fans and ventilation are you using?

ive run lights at night in the past..that may work or buy an air conditioner and put it outside the tent...if temps are that high there is somthing wrong /w ur intake or exaust..better ventalation is a must.

iam using one fan putting cold air in , got a small fan inside , got my light on 18/24 but its ready for 12 /12 just need tips as i dont want to leave door open when flowering