LED coverage vs actual watts

John Ames

Member
Hello,i have a question about led lights.
On the internet i find different suggestion and can't decide so im here :).
My grow box is 4*4*6,5 with 6 plants.
Im moving from hps to led (heat problems).
Some web pages tell that for a 4*4 i need at last 512W of actual led wattage...
Other pages (and some led light seller) tell me that i must look at the coverage of the lights not at the wats pulled from wall.
Any suggestions?
And if someone have some experience how powerful light to put in?
 

weednerd.anthony.850

Well-Known Member
A lot of it depends on your budget as well brother

if money is not a problem I’d recommend maybe an HLG or if trying to save every penny possible, @MarsHydrofactory makes some decent cheaper lights and I’ve seen some nice grows on here with both mars lights and other budget brands like spider farmer, or lights gotten from alibaba like Meiju or similar.

as far as wattage I’d narrow down options based on watts 480-600 watts should get you in range but remember manufacturers want to sell lights so a lot of their coverage suggestions and ppfd maps aren’t 100% accurate unless they independent ppfd maps done by another source.

For a 4x4 I’d recommend an HLG blackbird at 600 watts for $749, the 650r at 630 watts for $899, or at least the 600 Rspec at 600 watts for $699. I do not work for HLG I just have had only good experiences with their products and their customer service is top notch too and their lights all have nice dimmers so you can start lower and crank it up in flower as you see fit.

I currently have the Scorpion Diablo I got for a 4x4-5x5 closet that is 650 watts over 16-25 sq ft so about 40 watts a sq ft if I use 4x4 of it, but a lil shy of 30 watts per sq ft if I use every inch of space, say 5x5, for my canopy, which I typically don’t , I leave a small area that I can squeeze into and work on the plants in, but the ppfd spread makes up for raw watts with these Diablo quantum boards. Don’t forget I’m running CO2 as well.

Hope some of this helps you decide, and remember 30 watts sq ft minimum, budget will dictate brand, and if your ready to drop a lil cash on it go with HLG as their lights are true replacements for HID but do run a bit hotter than some other LEDs.. but I’d rather deal with the heat a lil bit with my 650w Scorpion Diablo vs 1000w HPS heat which is a lot greater even when I crank the Scorpion Diablo up and it is supposed to replace a DE HPS at full power.
 

Rurumo

Well-Known Member
I second HLG. I like to feel the drivers of my various lights just to see how hot they get, and man, some of my generic brand lights with meanwell drivers get HOT, even at 80% (which is typically as high as I run them.)...but the HLG 650R is just comfortably warm at 80%-Offhand I think they use Inventronics drivers. Anyway, that might not be huge to some people but this is the only light I've ever run that doesn't have "hot spots" on it, either on the quantum board or the driver-I think it's interesting. Also, keep an eye on what the light that these different LED fixtures actually looks like. I think HLG uses just white and red diodes, but a lot of brands throw in these yellow ones that creates a less enjoyable experience for me when watching my plants, and it also sucks for photos for some reason (like HPS but not as bad). I just wanted to throw a couple of more things out there to consider. For a 4x4, I think 500-600 watts is fine-I run my 650R at 80% in a 4x4 and wouldn't go higher with my environmental conditions.
 

rocknratm

Well-Known Member
Ideally, 50 w/sq.ft is the minimum, so 200w for a 4x4. 75 being better, 100 w/sq.ft. being better yet, and 125 would be great but:
If you already have heat issues, consider upgrading ventilation. Leds are better heat wise, but not always as much as people think.
 

LowRange

Well-Known Member
I'm a fan of using a couple of fixtures rather than one big one. You have redundancy if one fails, you can space them out to give more even coverage, you can independently adjust the height of each fixture to suit and you have to option to run a single light in a smaller propagation tent or area. Also you can get different brands of lights to give more range of light spectrum.
 

coreywebster

Well-Known Member
Ideally, 50 w/sq.ft is the minimum, so 200w for a 4x4. 75 being better, 100 w/sq.ft. being better yet, and 125 would be great but:
If you already have heat issues, consider upgrading ventilation. Leds are better heat wise, but not always as much as people think.
Not understanding your math , unless it's a typo.

480w minimum to 600w for a good LED
600w minimum to 1000w for HID.
In that space
 
Last edited:

dbz

Well-Known Member
Ideally, 50 w/sq.ft is the minimum, so 200w for a 4x4. 75 being better, 100 w/sq.ft. being better yet, and 125 would be great but:
If you already have heat issues, consider upgrading ventilation. Leds are better heat wise, but not always as much as people think.
4x4 is 16 square feet...
x50 is 800 watts...
That's doable but I'd be running CO2 in a sealed with that.
200 watts in a 4x4 would not produce good flower results.
Personally without sealed CO2 (no not just "bags) I wouldn't go above 40 watts per square foot.
 

coreywebster

Well-Known Member
Hello,i have a question about led lights.
On the internet i find different suggestion and can't decide so im here :).
My grow box is 4*4*6,5 with 6 plants.
Im moving from hps to led (heat problems).
Some web pages tell that for a 4*4 i need at last 512W of actual led wattage...
Other pages (and some led light seller) tell me that i must look at the coverage of the lights not at the wats pulled from wall.
Any suggestions?
And if someone have some experience how powerful light to put in?
There's LED and there's LED.

Luckily you picked a point in time when most of the market is at least half decent. Unlike 5 year ago when most of the market was still flooded with blurple rubbish.

Make sure your switching for the right reason, many heat problems can be overcome by proper ventilation or air cooling, LED is not a substitute for a poorly controlled half assed environment.
 

PJ Diaz

Well-Known Member
Heat loads are based on actual wattage not wether they are hid or led
While this is true, moving from HID to LED can still help to solve high heat issues for a few reasons. First off, growers typically need less LED wattage vs HID to cover the same space. Secondly, due to much less IR heat being thrown at the plant from the light source with LED compared to HID, the plant's leaf surface temp will stay cooler. This ultimately means that you can grow plants successfully under LED in higher environmental temps compared to HID.
 

dbz

Well-Known Member
While this is true, moving from HID to LED can still help to solve high heat issues for a few reasons. First off, growers typically need less LED wattage vs HID to cover the same space. Secondly, due to much less IR heat being thrown at the plant from the light source with LED compared to HID, the plant's leaf surface temp will stay cooler. This ultimately means that you can grow plants successfully under LED in higher environmental temps compared to HID.
To the point of which if IR isn't supplemented, you need to grow at higher temps than HID. IME.
 

John Ames

Member
Ideally, 50 w/sq.ft is the minimum, so 200w for a 4x4. 75 being better, 100 w/sq.ft. being better yet, and 125 would be great but:
If you already have heat issues, consider upgrading ventilation. Leds are better heat wise, but not always as much as people think.
Thanks! That helps! I will have a try.
 

John Ames

Member
A lot of it depends on your budget as well brother

if money is not a problem I’d recommend maybe an HLG or if trying to save every penny possible, @MarsHydrofactory makes some decent cheaper lights and I’ve seen some nice grows on here with both mars lights and other budget brands like spider farmer, or lights gotten from alibaba like Meiju or similar.

as far as wattage I’d narrow down options based on watts 480-600 watts should get you in range but remember manufacturers want to sell lights so a lot of their coverage suggestions and ppfd maps aren’t 100% accurate unless they independent ppfd maps done by another source.

For a 4x4 I’d recommend an HLG blackbird at 600 watts for $749, the 650r at 630 watts for $899, or at least the 600 Rspec at 600 watts for $699. I do not work for HLG I just have had only good experiences with their products and their customer service is top notch too and their lights all have nice dimmers so you can start lower and crank it up in flower as you see fit.

I currently have the Scorpion Diablo I got for a 4x4-5x5 closet that is 650 watts over 16-25 sq ft so about 40 watts a sq ft if I use 4x4 of it, but a lil shy of 30 watts per sq ft if I use every inch of space, say 5x5, for my canopy, which I typically don’t , I leave a small area that I can squeeze into and work on the plants in, but the ppfd spread makes up for raw watts with these Diablo quantum boards. Don’t forget I’m running CO2 as well.

Hope some of this helps you decide, and remember 30 watts sq ft minimum, budget will dictate brand, and if your ready to drop a lil cash on it go with HLG as their lights are true replacements for HID but do run a bit hotter than some other LEDs.. but I’d rather deal with the heat a lil bit with my 650w Scorpion Diablo vs 1000w HPS heat which is a lot greater even when I crank the Scorpion Diablo up and it is supposed to replace a DE HPS at full power.
Budge limited :-(
 
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