How much light, is too much light?

Hi guy! :grinning: hoping everyone is well.

Quick question today regarding lighting, and how much light is too much light?

I am wonder, for example, would six HLG 550 Rspec V2’s be too much light (3000 watt draw) for a 7 x 7 space? (2.4M x 2.4M).

Thankyou, and a wonderful day to you all!


This is a question for resident light guru. @dbrn32


Thought i heard 50 watts per square foot with a good light and 75 for the cheaper lights

1 Like

You would be able to run CO2 with that much light I think. But I’m not an expert.


4 hlg-550’s is probably plenty.


Thanks for all of the insight guys! :grin:

@dbrn32 would you agree with the comment above stated by @Tinman mentioning the 50W per square foot?
Which would make it 2500W for a 7 x 7 space, (2.4M x 2.4M) before any light gets wasted?

Just trying to figure out how much light can be used, without wasting it, with the addition of added co2 of course,
Or… how much light would be too much before it being a waste without adding co2.

Just super curious. :face_with_monocle:

Huge thankyou’s.


Sorry, for whatever reason I missed this tag. I do not necessarily agree you need 50 watts per square foot of lighting. That is old school hid generic rule of thumb used in place of explaining par, par per watt, ppfd average, and daily light integral.

Over the years lighting tech has increased a lot and some lights are producing as much as double the amount ppf per watt. These lights do not require as much power to hit recommended ppfd average in given space. These lights also usually cost significantly more, and they also usually list the total light output. So you can decide for yourself if it will meet performance level you are seeking.


too much, lol


All need help 1st time grower. Is this to much light or how would you experts use this in each stage? Thanks for yourhelp

This doesn’t put our very much light at all. @Montano55 I don’t mean to give you negative news on your first post. (First of all welcome to the forum!)
I would recommend HLG lighting, I’ve been down the blurple road, started there, and ran after I figured it out. Your biggest investment should be lighting. Just don’t want you to make the same mistake I did. The $1,000 in blurple lighting could have purchased some really nice lights. Now they sit in storage.

What space are you growing in?

1 Like

I heard 72k lumens is the absolute max of beneficial light before your plants just can’t work any harder and quite frankly unless your running c02 your probably not even benefiting from that much

1 Like


Welcome to the forum. There’s more info on here than you’ll know what to do with. I promise you you’ll grow some good weed if you follow the guidance of the friendly people you’ll meet on here!

Thanks for the help everyone :heart: & sorry about the late reply…

This lecture ended up giving me all the answers I was looking for:

Definitely worth the watch. :grin:

1 Like