2 600w ?!?!?

for 15 to 20 plants?

2 600w MH for veg
2 600w HPS for flowering

or how about 2 of these http://www.littlegreenhouse.com/accessory/lights4.shtml
instead of investing in 2 sets of each

anyone got some info?

IMO you dont need 2 600w MH to flower under 2 600w HPS. Maybe Veg under daisy chained t5s or 1 400w/600w MH

ptone said:

IMO you dont need 2 600w MH to flower under 2 600w HPS. Maybe Veg under daisy chained t5s or 1 400w/600w MH

Click to expand...

Agreed. Those dual arc bulbs are kinda BS, IMO

if i were you i'd veg for 24 hours a day with 1200 mh with 20 plants for 3 weeks. than veg for 18/6 with 1200 hps and veg for another 2 weeks with that. i notice this helps the plants transition to the new photo-period a lot easier. after the 5 week veg i'd flip them and use 1200 hps for flower. i am assuming that you are growing from seed. if you are growing from clone just veg for 2 weeks mh and 1 week hps.

You want more light during flowering than in veg.

Take this as an extremely rough guide:

• A 250 watt fixture will supply enough light to cover a 2.5 foot by 2.5 foot grow area. (6 plants or less)
• A 400 watt fixture will supply enough light to cover a 4 foot by 4 foot grow area. (12 plants or less)
• A 600 watt fixture will supply enough light to cover a 5 foot by 5 foot grow area. (18 plants or less)
• A 1000 watt fixture will supply enough light to cover a 6.5 foot by 6.5 foot grow area. (30 plants or less)

You can grow more plants if you use a light mover.
For instance, one 1000watt MH light can successfully veg 400 clones while on a light mover.