Introduction and a question

Hi Everyone. I have been a member for a few months now and have been doing more reading and research rather then asking questions. I am a medical card holder in the state of Michigan, I am new to growing but, not new to the scene. I have just recently finished my first grow I did 3 L.S.D. & 2 White Widow. The equipment used in the first grow was a 400 watt with the dyna grow line, fox farm beastie bloomz, cha ching, open sesame and Bud Candy for my sweetner. My room size was 3.5'L3.5'Wx7'H and I think my temps were in a tolerable range. With lights on avg temp was 73* with lights of 66*. I have just recently started my second cycle. This time I have added another 400 watt light and have double my room size to 6.5'Lx3.5'Wx7'H, but am doing 12 plants 4 headband, 4 vanilla kush, and 4 blue cheese. Now for my question. Since I have added the second light my room temp is up to 74-75 and the canopy temp ranges from 77-79. Are these temps inside a tolerable range?

I find that up to 86 (but never above 90 without co2) you are safe as long as your humidity is not too high and your tops aren't burning (hand check).

Yeah I stuck my hand above the tops and its was barely warm at all. What would be the easiest way to add co2 to a room of that size?

A easy and quick way to add co2 is get a 5 gallon bucket and mix up a sugar and brewers yeast mixture. Here is what I use:

5 gallon carboy or brewers bucket with lid.
An Air Lock for the top to let co2 out but nothing into the mixture
4.5 Gallons of Water at a temp of 75 degrees F
3-4 LBS of Dextrose Corn Sugar of regular sugar if you don't have access 2 cups equals about 1 lbs of sugar
And one pack of brewers Yeast.

Mix it all up and put it in the room you will see the air lock bubbling after approx 2-4 days. Should last approx 1.5 to 2 weeks longer if your lucky and use quality yeast.

Its quick and dirty and cheap. You can find everything at a home brew supply shop.

Hope this helps. Happy 4.20 Eve

Great thanks! A buddy told me to try dry ice in a styrofoam cooler and cut a hole in the top of the cooler and put in front of an oscillating fan. Not sure about his idea tho. Has anyone tried that with the dry ice? If so approx how long would a cooler full last in a 77-79* room? Most likely go with the option noted above.