sandman said:
Hi there!
I have a space I'm going to start a grow in.The measurments are 7ft.deep,6ft.wide,6ft. tall.
I already have a dayton fan for intake and a bathroom fan for exaust.What size of lights will I need?How many?
The room was used before by relatives,but now it's just storage.The wiring is already in as well. Any help would be great!Thanks!
P.S.Is a bathroom fan for exhaust too small?
Hey Sandman, nice sized room to grow in man! You'll see lots of numbers for lighting lumens per/sq ft, but they will all be between 3,000 and 6,000. Pot will grow ok under 3,000 and even as low as 2,000, but not as well as 6,000. How much light you need depends on the strain you're growing, the reflectors you use, the distance from the surface of your plants, the general health of your plants, the type of nutrients you use and more.
I calculate for 5,000 lumens per/sq ft, and I use 430 watt HPS Hortilux bulbs at 18 inches. For my hydro grows, that works really well.
You have 42 sq ft of area in your 6 x 7 room.
Lets calculate for 5,000 lumens per/sq ft
5,000 x 42 = 210,000 lumen output is what you're looking for as a total.
A 430 watt Hotilux produces 58,500 lumens.
210,000 divided by 58,500 = 3.6 bulbs you would need to produce 5K Lumens per/ft, or say 4 lights.
This works very well actually. You can use four 430 watt bulbs and get great coverage in your room. The positioning of your bulbs should be so that at 18 inches from the tops of the plants, the light reaches just to the edge of your crop and a little on the wall. This should make all of them overlap some in your room. That's perfect. Position and hang your lights before putting anything else in the room. It'll be way easier to see and move. I would also suggest using the "bat-wing" reflectors. They have a great throw and would work very well in your room.
Paint the walls with the brightest flat white paint you can find. Ask a paint store guy for the brightest flat white, he'll know his stock. I use "Behr" Premium Plus Ultra Pure White #1050.
Is the room airconditioned? Are you growing with dirt or hydro?
Tell us about how you intend to grow and what strains if you can.