How much Hotter is MH than HPS?

ummm...that 1000w will be puttin out some heat man...i wouldnt risk it and id go get a 600w hps. it would prob raise your temps another 5 degrees. but u do have co2, so im not positive how much more heat they can take with it

Keep the 1000w! ESPECIALLY if you are going to use MH! Metal Halide doesn't penetrate the canopy as well as an HPS, so those extra 400w would be ESPECIALLY important. If I were in your position, I'd save the money from a 600w bulb and buy an oscillating fan or two. Fantastic for strengthening the plants, and great for keeping it cooler!

sounds to me like it was a 1000w hps...

i have noticed that mh's do burn hotter than hps bulbs for sure.. i would really think of dumping that one k bulb just for the summer and run the 600 watter.. i'm sure the benefits you'll get from no or less heat stress will more than make up for any benefit that the added lumens will give you.. added lumes is a benefit, but when you add in the added heat, i don't think the trade off is really worth it.. i've found out heat is a bigger detractor than the added lumes are a benefit..

ya man...i burnt the shit outta my plant. one day, and i had just changed the bulb, and left the light at the same height...ya 5 min. later like 8 leaves were yellow, and twisting. it was dumb...lol

yah, i was growing with a 250 watt hps/ mh in about a 3 x 3 x 6 area, and i went and got a 400 watter, and i'm really pushing the limits of my lil closet with heat issues.. i honestly think i was better off with the 250 watter, but it would kill me to have to go backwards, lol, so i've been fighting if trying to figure things out slowly.. did a nice job of burning my last grow some what though.. it's not horrible, lol, but it's definitely not as good as it would have been if i didn't have the heat issues, that is for sure.. plus, it seems like i'm adding a couple of weeks to my flowering times too.. not sure as this is my first run with these strains, but i'm running larry by cali connection and i just took them down at 10 weeks when it's said to be an 8 or 9 week strain..

^^^^Bro how r u having trouble with heat i run a 600w in a 4.5x2.5..No vent only outside boxfan but it only gets around 80-sometimes 90 here outside...Better bang for buck with the 600w