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LED coverage vs actual watts

Hello fellas,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?
Ty
 

Cannibcody

Well-Known Member
Re: Led coverage vs actual wats

Hello fellas,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?
Ty
I've read more often than not that you wanna go by actual watts....but I'm just starting out with leds myself so hopefully someone with a lil more experience can chime in....i have one 600w mars hydro in a 30in by 30in by 7ft box an coverage seems to be great....i plan to get a second light once i get closer to flower just to help fatten up the buds when they start forming
 

TJTrouble

Active Member
In general, I think it is pretty important to consider both coverage and actual watts. Coverage can change based on optics, which means you can have two lights with the same wattage and they can both have different recommended coverages and mounting hights.

Spectrum, and PAR output measured in micromols, are also important factors to consider as sub par LEDs (bottom bin, off peak/off spectrum) will provide less usable light at the same wattage as top bin LEDs.

Long story short, buy from a trusted manufacturer, or a fixture that others have shown to be successful with. Unless of course you don't mind doing a metric buttload of research on photosynthesis, LED technology, and the like. Hahaha. It can get seriously involved if you go that route.
 
TJTrouble thanks for the reply.
I checked all the stats you mentioned and i think i made my decision.
I allready have this one:
MEIZHI LED Grow Light Full Specturm 450W
And i will add this one:
MEIZHI LED Grow Light Full Specturm 900w
Hope will be ok for my situation...what do you think?
 

TJTrouble

Active Member
Considering the price and box led format used, you can expect that they are not using top bin diodes. They also provide rough ratings for the diode spectrum, and the whites are listed simply as "white" which isn't helpful. The power supplies are cheap bricks strapped into the housing which is pretty commonplace with these cheaper fixtures. They don't show the heatsink, if any are even used. Sometimes they just use a sheet of aluminum, rather than one with fins, which usually leads to early diode failure. I also couldn't find the wattage of the diodes used. Nowadays, it is commonplace to use 5 watt chips and underdrive them to keep them running cooler and extend longevity. If 3 watt chips are used, they tend to burn out faster, especially in cheap fixtures.

They do seem to have alright reviews, but I can't say the experience level of the reviewers on Amazon, or how long they had the product before reviewing.

I am guessing by the looks they are similar to the least expensive MARS fixtures.

I personally don't go for fixtures that don't provide all the information I am after, or look to be cheaply built. But many do and find success with them. The question is how much better would your yield be with a higher quality fixture, and how many grows will you get out of the fixtures before they begin failing on you.

Edit:

Admittedly I only did a quick search on the brand and fixtures you mentioned, so there could be more info out there I did not site and take into account.

I am also by no means bashing the brand or saying they are a waste of money; I am just trying to help set expectations based on the information I found.

I am personally using one brand that is quite new to the scene but shows excellent promise for blooming, and another that has been tried and tested with results, but also lacks enough red end of the spectrum for proper bloom.

Sometimes the best result for the budget is to mix things up so that each fixture helps offset the weaknesses of the other. Or to just raise the budget!
 
All written on ebay under the item description:
The wattage is 5W
900W LED grow light
Specifications:
-Spectrum: White, 450~475nm, 620~630nm, 650~670nm, IR.
-Par Value: 1260 umol
-LEDs Quantity: 180Pcs
-LEDs Brand: Epistar, Epiled.
-Amperage: 1.92A@AC220V
-Power draw: 405W±5%/220V
-Equivalent to HPS/MH/HID: 450W
-Color of Outer Casing: Royal Blue
-Lumen: 27589Lm±5%/220V
-Product Dimensions: 22.05*12.60*2.76inches(560*320*70MM)
-Decibel of the light: Around 57 DB
-Net Weight: 6.1KG(13.5lbs)
-View Angle of LEDs: 90/120 Degree Mixed
-Working Temperature:-20℃~40℃(4℉~104℉)
-World Voltage: AC85~265V
-Lifespan: 50000-100000 hours
-Heat Sink Size:5.04*4.61*0.39 inches * 6PCS
-Power cord length : 6.56 ft ( 2 meters standard)
-Growth Coverage (At Height 18'') : 5*3.5ft
-Bloom Coverage (At Height 18'') : 4.5*3ft
-30 DAYS RETURN GUARANTEE!!
Package includes:
-1 X MEIZHI Reflector 900W LED grow light
-1 X Hanging Kit
-1 X 6.5ft Power cord (Uk plug/EU plug)
 

TJTrouble

Active Member
You'll notice the spectrum is not precise but rather ranges. It should be fairly precise with top bin diodes. Also "white" means very little. There are tons of white LEDs and the CRI makes a difference along with the actual spectral output. You'd need a graph for each LED to get a really good idea of what it is actually contributing.

5w is Good, but look at the thickness of the heatsink. It is 0.39" which is basically a flat board of aluminum. Does the one you currently have, have fins? If not that is a red flag for me personally.

A lot of what you posted is what I found, minus the diode wattage, that didn't seem to be listed on Amazon, or I was glazed over and didn't notice.
 

Skullman420

Well-Known Member
Use someone who use good diodes. Mars Hydro pro series or Growant - both sponsors of this great community
 

Skullman420

Well-Known Member
One year warranty on the meizhi. That's a little on the low side.
 

Skullman420

Well-Known Member
My point exactly - go for a sponsor of this page. Preferably one that is active here and can help you out if you run into problems
 

TJTrouble

Active Member
Yes it have fins and i must say that the heat disperse very good...the pannel is cool on touch
If you are comfortable with it then use it. I can merely give you my opinion based on experience with 50+ led fixtures used across a few industries. At the end of the day, remember that there is a price difference for a reason. You can't buy a Ferrari for the price of a Kia, and there definitely will be performance differences on the track.
 

GodOfPot

Well-Known Member
Yeah we have some good sponsors, there's some good lights out there, can get very pricey though.

If price is a driving factor for you in choosing that light, have you considered HID set ups? You'd get much better results imo for the price.
 

Merkle420

Well-Known Member
If you are comfortable with it then use it. I can merely give you my opinion based on experience with 50+ led fixtures used across a few industries. At the end of the day, remember that there is a price difference for a reason. You can't buy a Ferrari for the price of a Kia, and there definitely will be performance differences on the track.
That's all well and good, but how long is the ferraris warranty? We get a 7 year unlimited K warranty with hyundias here.

Oh and an exhaust swap on a certain Ferrari can be upwards of 15,000 considering the tranny needs to be taken out, just saying.
 

JuanCarlos

Well-Known Member
If you are going LED strictly because of heat, I would tread lightly. If you are going from 600 watts of HID with a ballast outside the grow area to 600 watts of LED you may be surprised to find almost the same amount of heat.
 

gbauto

Active Member
If you are going LED strictly because of heat, I would tread lightly. If you are going from 600 watts of HID with a ballast outside the grow area to 600 watts of LED you may be surprised to find almost the same amount of heat.
This is precisely what you're trying to address.
To match and surpass HPS on it's ability to convert energy into light requires top shelf components. If you're willing to pay for state of the art components then it's possible to get the same amount of light with less watts-this also means that there is less heat load because of higher efficacy.
 
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