400W CMH or 600W hps in 2x4? (Flowering)

Hi folks, I am trying to decide on which light to use in my 2x4 tent. The options are in the title, a 400w CMH or a 600W hps, in a sun system 2 reflector (air cooled, spitting the heat out in the same room as the tent). I am definitely using the 400W for their first few weeks of veg once I transfer them into the tent (Veg cab uses 250W CMH)

I have a seperate room where I exclusively use CMH bulbs, and I think they are amazing! Unfortunately I can not afford 2 250W HPS ballasts for the tent in question.

So, which would you choose, and why? I know the CMH is better than other 400W options, but is the enhanced spectrum really better when compared to what a 600W HPS can do?

Lastly, is the heat concern. The tent will be in a larger room, that has 1 A/C vent that will help cool it off a little, but last run I experienced room temperatures in the mid to high 80's using a 600W HPS. Would using a lower wattage bulb be worth having a cooler environment to maximize plant growth?

I think I am starting to ramble, so I will stop here and get your feedback.

use the 600w if you can handle temps.

If you cant handle temps, maybe use the 400w. Too bad they only make those CMH bulbs in 400w and less...

Clown Baby said:

use the 600w if you can handle temps.

If you cant handle temps, maybe use the 400w. Too bad they only make those CMH bulbs in 400w and less...

Click to expand...

they are working on a 600w bulb from what i hear that would be amazing. i also read that they are trying to make the lower wattage bulbs better yielding than higher watt. i know we have all heard that before but its never bad to hope haha

Clown Baby said:

use the 600w if you can handle temps.

If you cant handle temps, maybe use the 400w. Too bad they only make those CMH bulbs in 400w and less...

Click to expand...

jdmcwestevo said:

they are working on a 600w bulb from what i hear that would be amazing. i also read that they are trying to make the lower wattage bulbs better yielding than higher watt. i know we have all heard that before but its never bad to hope haha

Click to expand...

http://www.growlightexpress.com/pages/ceramic-metal-halide-pv-c0-2.html This is a retailers website. I have found multiple sites that are offering 250W CMH and 400W CMH. Just some information for ya. Also no i am not affiliated with them in anyway. Google just happens to be my best friend.