Proper watts for a 2ft x4ft grow area

I am upgrading my T5 lighting. Going to go with led. I read that 50-60 watt per sq ft is ok to grow in, that said I would be looking at a 400 to 480 watt led. I was hoping to go with a 600 to 800 watt led. I guess what my question is if I do go with higher watts is that going to be over kill or is that ok for autos?

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No …the more the better. just watch the heat and you’ll be fine.



Keep it cool. I ran a vent from my ac into my tents.

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There is such a thing as too much light, it is called photoinhibition.

50 watts of LED, actual power used - not what the light is labeled, is probably about the most you want to use per square foot. And this would be true for all contemporary common LED models.

With some newer LED models, as low as 25 watts per square foot is enough. However most recommend around 30-40 watts per square foot with most quality mainstream LEDs.

So… 2ft x 4ft = 8sq. feet. 35 watts x 8 = 280 watts. So a 600 watt LED that actually uses about 300 watts would be more than enough for that area.

30 watts x 8 = 240 watts

50 watts x 8 = 400 watts

So I’d say any light that is between these numbers would be a good light for your area.

50-60 watts per square foot is the amount that has been used for HPS forever, it might work for T5’s as well, but the newer LEDs and CMH/LEC are much more efficient in electricity to PAR conversion, and much less energy is converted to unwanted heat, so the recommended watts will be very different.

Happy growing,



Ive got 2x4x6 tent and have two MarsHydro 600 there first gen LEDs true watts each light 274 or so my total watts or true watts is about 540 and my plants love it

25 days from breaking soil
And there also auto flowers

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thanks for that info. there is a lot of info on the web sometimes it gets a little overwhelming. you are the best MacG.

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thinking I might go with a platinum led p450. they are pretty expensive so id like your thoughts about this light, will it meet my needs?


Platinum LED is considered one of the best and most reputable manufacturers out there.

And the p450’s shape/format should have core coverage that will work with a 2’x4’ area. It will likely work very well for you. You could, but I don’t think it is necessary to go up to the p600, and I don’t think there would be a huge benefit.

Happy growing,


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There isn’t much difference between a platinum and a mars LED other then price
Same parts inside, platinums look nicer with the custom body
Both mars and platinum have a good name for entry level LED grow lights
With the new mars pro2 I think mars are alittle in front now but you cant go wrong with ether

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With led you can get way more use of watt if you use certain spectrum. I have an led × 2, 300 watt but way different spectrum then marshydro and get the same yields. Its about knowing your enemy.

thanks everyone for your help. I hope I’m on the right track with a proper grow room. just want happy girls.

Yoo @pops, where’s Mordecai and Rigby? :evergreen_tree::evergreen_tree::v:

I have the same type tent. I have 346 true watts. Led. I have two sunspec light with and ultraviolet light that is perfect. Look up par coverage in led for your size tent . Or look up light limit for your liking.

My first grow with both a HLG 225w accrual watts is 235w a SABER 150 really 165w true watts 400w in a marshydro 2x4x6 PPFD in corners is 500-550 the next closer ring around the middle is 625 the middle and edges are 700+ the 225 is at 24 inches above canopy at lowest wattage the SABER is at 20 inches above canopy I have 5 going on 4 rescue plants I can’t find out how much yield I should roughly get from 4 to 5 plants in there all TOPPED @ the 6th node