Help with 1st grow room: Heat? Plant count? 600W HPS + 100W CFL x8

Whats up RIU members. This is my first post so I wanted to properly introduce myself. This is my first time growing and I just finished setting up my grow room super late last night. Its a 8ft wide x 15ft long finished attic. The ceiling is 9 ft tall and I hung a 600W iPower interchangeable MH/HPS (bat wing reflector) and I have a total of eight 100W equivalent CFL'S. I have a total of fifteen buckets that can hold 5 gallons. I want to set up 3 rows of 5 (3x5=15). I checked my light coverage and it looks like I can cover all buckets and supplement dark spots with cfls but I wanted an experienced growers opinion. I successfully sprouted some seeds (regular) from nirvana. I have 5 New York Power Diesel, 5 Aurora Indicas, and 5 Wonder Woman seedlings in solo cups. They sprouted 10 days ago under the 8 cfls and are awaiting to be transplanted into the buckets

*1st question: is this enough wattage to produce good growth? I was afraid of my bill being too high and my few option to control heat with a 1000W set up.

*2nd question: Will it get too hot? I opted out of buying a cool tube because I have no place to vent my attic except though the entrance door. The windows are "sky lights" so they dont open. All access to the outside world are walled off with drywall and I dont want to cut holes because Im renting. I do have central AC and 2 standard box fans to keep air moving in the grow space but being that heat rises, its a 3rd story attic, and the 600W puts off additional heat, im in a bit if a predicament. Current ambient temps have averaged between 68-78 F WITHOUT THE 600W light being turned on ( its end of fall/beginning of winter in North Eastern USA). I did a test run late last night and left my MH light on for 8 hrs with the door closed, no AC, no fans running, and checked the temps every 30 minutes. Test results showed a 3 degree F temp increase every 30 mins and topped off after 5hrs. In short, temps in the grow space increase by 10-15 degrees F when I turn the light ON (reminder, door closed, no AC running, no box fans running).

3rd question: with 15 kids growing (in a 8ft wide x 15ft long x 9ft tall space) will they run out of CO2? Remember, the only way I have to vent the room is with a single wall vent connected to central AC, 2 box fans and the entrance door.

Sorry for all the details in advance, I'm a very "exact" type of person. Any help/advice would greatly be appreciated. I hope my diagram pic shows up. Entrance door on lower right corner. Rows of circles are the buckets. Sun shape is the 600W MH/HPS. Rectangles with arrows are box fans. Left wall with arrows show single central air vent.

I'm saying if your temps are already upper 70's you're probably gonna need a supplemental A/C unit. ONLY using 400w of CFL bulbs my grow room temps averaged +10deg to whatever ambient temp is. Although I am growing in a 2x6x8 closet, not a whole room. I really have no idea how much more heat a 600w HPS will add, I've got no experience with HID yet.

ii dP ii said:

I'm saying if your temps are already upper 70's you're probably gonna need a supplemental A/C unit. ONLY using 400w of CFL bulbs my grow room temps averaged +10deg to whatever ambient temp is. Although I am growing in a 2x6x8 closet, not a whole room. I really have no idea how much more heat a 600w HPS will add, I've got no experience with HID yet.

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Thanks for the input. Ive been keeping a very close eye on the temps. Im going to experiment with different options. Temp today is 63 F outside. Attic temp was 74 F. I switched my 10 day old plants over to the 600W MH and the temp went from 74 F to 85 F with the door open and the fan on. I'm closing the door and watching closely how much higher it will climb.

My biggest fear is that I wont be able to use it after winter is over because of the heat, so I'm glad I went with 15 buckets. Hopefully I produce enough to last me the year

sorry I didn't even try to answer the other questions lol...

I don't know about the 600 being enough coverage for 15 plants actually.... I'm looking at this chart that says 1 square meter. which is like 5' x 5'. That's pushing it with 15 5 gal buckets. You could go the cheap route and supplement the sides with CFL's.

As far as C02, as long as they have a steady source of air coming into the grow room from somewhere outside the grow room, they should have enough. However, you can always grab a small co2 canister from a gas supplier near you. I'm sure you can find some kind of cheap DIY timer or something, or just run some hose from the canister over to the girls and crank that baby open once or twice a day, flood the room and be sure of it.