What size lights should I be using?

Hi Everyone,

I am currently planning a new grow which would be larger than the small closet grows I have done in the past and have some questions I’m hoping someone can shed some light on.

I plan to use:

  • 8ft x 4ft x 6ft tent
  • HID lighting
  • Air-cooled hoods with an exhaust fan and ducting to cool the lights
  • Carbon filter and exhaust fan to scrub the air
  • Coco coir in fabric pots with organic liquid nutrients
  • dehumidifier
  • Feminized white widow seeds using Scrog

Would it be overkill to grow with two 1000 watt lights? Or should I be using 600 watts instead? and how many plants can I realistically fit under the 1000w or 600w?
I am looking to get maximum yield and potency possible.

Any info would be greatly appreciated, Thanks!

Good question. My first thought is 600w x2…

Second thought is, what kind of yield will that produce? 3 pounds? 4?


I’ve read some articles that say 2x 600w will be sufficient for the space but i’m wondering if the 1000w will provide fatter buds and higher yields or if it the heat and electricity costs will just cause more problems than its worth…

4 pounds would be a win in my books…

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Look into Spider Farmer. I have (2) 2000s. Heavy flower 6x6.

All Samsung LED. I overkill 4x4


Can go either way, 600 or 1000 watters. The 600’s are the most efficient of the HPS family and 2 of them will do a fine job in a 4x8 tent and would be easier to keep temps in control than the 1000 watters. But if yield is your goal, the 1000 watters can outgrow the 600’s but there will be much more heat and need more ventilation or AC to deal with it. I’d do 2 600’s with 4 topped plants under each light.


I agree, get yourself two good air cooled 600’s and call it a day.


Okay, that makes sense. What size pots would you go for?

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@Rgrowfarms. If you’re going for max yield then I’d go for 10 gal pots and veg a bit closer to 9-10 weeks before switching to flower.
Any less time and the plants don’t seem to develop the size or maturity to produce the larger harvests.
Not saying it can’t be done but generally larger plants = larger harvests.

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Get a pair of 1000 watt fixtures with digital dimmable ballasts. That way you can dim them down to 750 watts(75% power setting) or crank them up to 1000 watts as you see fit.
Be sure to use good quality fixtures like XtraSun and Quantum or Prism ballasts, not one of the knockoffs.


I go from solo cup to 3 gal plastic pot to 7 gal fabric pot.

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Thanks to everyone for their input, really appreciate the advice!

Happy growing :v: