Max watts for a 2' by 2' single plant grow?

UpstateRecGrower said:
I've done 50 and it was too much with 70x 304's, how high are your lights and what size room? wondering how much of your light is being lost into the wall or floor if you keep them higher? How much square foot is each 288 covering? Mine are almost 1 for 1..
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Ill take measurements a d report back. Its important to note that you have to work up to high intensity. Par and ppfd are better measures of course.
 
Hot Diggity Sog said:
Ill take measurements a d report back. Its important to note that you have to work up to high intensity. Par and ppfd are better measures of course.
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Cool thanks. They did seem to like it early on, they prayed really hard, but later in bloom they foxtailed realllllly bad lol, some strains much worse than others.. It got me kind of thinking that maybe that can take more light earlier on, like maybe week 2-6 or something like that, and then back off, was what I was going to try at some point..
 
UpstateRecGrower said:
Cool thanks. They did seem to like it early on, they prayed really hard, but later in bloom they foxtailed realllllly bad lol, some strains much worse than others.. It got me kind of thinking that maybe that can take more light earlier on, like maybe week 2-6 or something like that, and then back off, was what I was going to try at some point..
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Ive had some foxtailing issues. Not convinced its the lights but could be. Def strain specific and even cultivar specific. But the trade off is huge dense colas.
 
You cant have too much light. Now there is a point of diminishing returns. And after that certain point. The airflow, humidity, temp, co2 and everything else has to be perfect to use the light. Dr Bruce bugbee discusses it in one of his lectures. Im running 47.5w/sqft in my 4x3 (570w from the wall). From all my reading it seems 50-55w per sq/ft of decent led is about the max for the average home grower. Most people seem to stick with 35-40w.
 
UpstateRecGrower said:
You absolutely can have too much light. I've done it on more than one occasion.
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Dr bruce bugbee seems to know his stuff. All plants can be pushed hard with light. Its knowing what and how to keep the conditions right for that plant to actually increase yield. 9/10 times thats beyond most peoples abilities in their home or even on small scale commercial grows. Everything from oxygenating the soil, to keeping temps in check. To co2 levels, the fact different nutrients will get absorbed differently. From pheno to pheno of the same strain. Like I said. Theres a point of diminishing returns. And when you are pushing limits and crossing boundaries others havent. you will lose some of them returns in the process
 
SmokeyExcursion said:
Dr bruce bugbee seems to know his stuff. All plants can be pushed hard with light. Its knowing what and how to keep the conditions right for that plant to actually increase yield. 9/10 times thats beyond most peoples abilities in their home or even on small scale commercial grows. Everything from oxygenating the soil, to keeping temps in check. To co2 levels, the fact different nutrients will get absorbed differently. From pheno to pheno of the same strain. Like I said. Theres a point of diminishing returns. And when you are pushing limits and crossing boundaries others havent. you will lose some of them returns in the process
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Bugbee grows lettuce and hemp, not high THC plants. The dude has a lot of good info, but take it all with a grain of salt. I guarantee you that some plants will reduce yield upon being subjected to overabundance of photons.
 
PJ Diaz said:
Bugbee grows lettuce and hemp, not high THC plants. The dude has a lot of good info, but take it all with a grain of salt. I guarantee you that some plants will reduce yield upon being subjected to overabundance of photons.
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Exactly. At some point any strain will suffer from too much light, some 1200ppfd, some 1500ppfd, but there’s just no such thing as “no such thing as too much light” lol
 
UpstateRecGrower said:
Exactly. At some point any strain will suffer from too much light, some 1200ppfd, some 1500ppfd, but there’s just no such thing as “no such thing as too much light” lol
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I think part of the problem is that if a grow space is height limited people run into this issue far more quickly than in situations where you can just raise the lamp higher. No doubt many are burning more electricity than they need when lowering the lamp at lower power would achieve the same effect. It's easy to say you can run 1000w per plant without burning leaves, because you can, it just requires the lamp to be further away.

Also, in smaller tents, where a lamp's coverage at recommended height is larger than the area of the tent, the extra light is being reflected onto the plants, so PPFD is higher than manufacturers specs would suggest.
 
PJ Diaz said:
Bugbee grows lettuce and hemp, not high THC plants. The dude has a lot of good info, but take it all with a grain of salt. I guarantee you that some plants will reduce yield upon being subjected to overabundance of photons.
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i think he grows medical mj too.
but "only" at 800ppfd if i got it right (maybe no co2 avaiable?).

one prob also is that not every led is the same.
were mixing up all kind of leds here with partialy vastly diferent ppfd per watt outputs.
hanging height, open space, non open space, amount of absorbing plant matter in the tent, all factors too.
guessing a 100W modern, well placed, leds would do well on just about a third of a square meter (2x2), these tents are seldon tall.
 
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I have limited grow space, so my flower tent is only a 2x4. So I try and use as much light as possible for max results. I also have a 7 foot tall tent, so height is really never a problem. I try and over filter the tent using a 6inch vortex S-line fan to pull the heat out.
I'm currently running 83w true watts per square foot in my 2x4 tent. Down from 100w per square foot. As long as you can control the heat you will be good.
My current light is 665w
Temps get as high 80f but usually I keep it at 76-78f
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Current grow under the light
Day 49 Tropic Lightning - Ocean Grown Seeds
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it replaced this 800w 10 CXB3590 light. The puck is a rapid led far red.
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Cheers
CCG
 

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How much PPFD a plant can absorb is purely genetic, and I have no doubts to much light can hinder the growth of some strains.

If a certain strain has evolved in an area that the sun is not overly powerful, the plant is probably not going to benefit from 2500umol, and will in many cases have a negative impact on the plant. It has simply evolved, and will do its best on a modest level of light.

On the other hand, some plants will do like crap, unless theyre blasted with light.

Plants that have evolved along the equator routinely get 2500umol of light. Not to mention extreme levels of UVA/B.

PPFD of full sun (meaning the maximum amount of sunlight we can receive on planet earth, e.g. on equator at noon) is around 2500 umol/m2/s. At approx. 45deg north of equator

Duke Diamond VA used to tell people how many umol many of his strains did best at, and none exceeded 900umol, and he stressed this on Granny Skunk. The first time we grew these strains we stunted them with to much light.

Granny Skunk...... Duke Diamond
Growing Notes – Grow larger sized bushes, plants only stretch .75:1 to 1:1 , stripping the inner most nodes and lower shaded areas will help you to stack on a lot of weight up top. Some phenos show light sensitivity issues with the lights too bright. I found starting bloom around 500-600 umol m2 and then gradually working up to 800-900 umol m2 worked the best.
 
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