how much cfm would i need?

I'm just thinking for the future.

I'm thinking of 2x1000 watt for flower, and my current 600 watt for veg.

If I were to run an inline fan for cooling, what would I need?

It would be running through a tent with the 2x1000's, then a curve to the veg tent with the 600, then unsure where I'd be venting. So there would be a few corners that the air would have to travel through

Also, any suggestions for fans that may be cheaper than the hydro store? Home depot maybe?

How big is your tent? (LxWxH) Those fans are based on room size. You want to exaust your room 5 times per minute.

oh, ok...the hoods are the type with the 6" in and out with the glass shield, so i didn't think the tent size had anything to do with it.

im thinking 4 foot deep x 8 foot long x 7 foot high.

guess i can do the math myself. lol

this is all speculation, as I don't have this equipment yet. Just trying to project what i need to spend for my next grow

In general you should replace the air twice a minute so double your cubic space. You have 224 there so running something 440 and up should be sufficient.

I'd go with something like this link... 1,000 - 1,200 cfm would do you great with a freash air operation using 2x1000 HPS >>> http://www.hydrowarehouse.com/ecoplus-ecoplus-supreme-12inch-inline-fan-1060-cfm-p-1686.html

...hey man, I just found some info for ya. My above suggestions were overkill unless heat becomes an issue.

1. Get the volume measurement of your grow room. You can determine that by multiplying the room’s length by the width and then by the height. For example, if your grow area is 9 feet in length, 12 feet in width and 10 feet in height, that is (9 x 12 x 10), your grow room’s volume measurement is 1080 cubic feet.
2. Compute the minimum cubic feet per minute that will be vital for the exchange of the air in the grow room. The grow room exhaust fan should exchange the air in the room at least once every three minutes. So, divide your number of cubic feet by three minutes to calculate the minimum CFM (1080 / 3 = 360 CFM).
3. Add 5 percent to your minimum CFM if you are using carbon dioxide enrichment. Therefore, if your grow room has a 360 CFM, add 18. You will get a result of 378, this is the actual minimum CFM requirement in order to ventilate your grow room.
4. After calculating the minimum CFM, you can now choose the best size of grow room exhaust fan that will perfectly suit your grow room.

Call me a tent newbie but why does the entire tent size matter if the air is being sucked through the hoods, and out the other side?

and thanks for that info. i got more learning to do.

i plan on building a tent with panda film, and pvc piping. Big enough to do SOG style growing with the 2x1000's

Go buy an 8 inch fan. craigslist for the fan around 100.
Get a rheostat so you can control the rpm. about 20$
get the 8 inch hooded reflectors.
get a timer aswell

You still need to exchange the air within the tent. But if you plan to run other fans for that, or add CO2 you can surely cut the CFM down and used sealed exhaust. Regardless to all that math though I'd stick with the twice a minute, espcially if your just pulling through the lights. Your not running a straight line exhaust so you'll lose airflow and if you add a carbon filter you'll loose some more. Spring style flex pipe cuts into it as well.

hmmm ok thanks for the input. what do you mean "sealed exhaust"? you mean just no leaks in the ducting?

...what WF is saying, "sealed exhaust" I believe, in different words...would be, the air cooling the lights would not be pulling the air from inside the room to cool them...the lights would be completely sealed off and pull air from another area. Most co2 growers, as myself, use this method to have complete control of the co2 level in the room. Your scrubber would need its own fan.