How much is too much light?

B

Bookush34

Well-Known Member
I am wondering how much light is too much light.

I have a 3x3 tent set up. I have a custom built air cooled 500watt Cob I built using vero29s from timber grow lights. I have a few years of running this set up and i can run it dialed right in. I grow in 5gal hempys with 100% perlite. Using a SCROG. I can pull 12-16oz depending on a few things.

My existing set up gives me a 55w/sqft print. It works good but still at the base of the screen I get some larff fluff.

Now I have two mor light set ups from a different endeavour that are not being used. They are 240watts COB Citizen 1212s. They are configured 4 in a row and fit snug beside my air cooled vero29 hood.

If I run both the Citizen1212 bars I will be looking at a 108w/sqft.

I’m hoping to get a little more light penitration down to the screen. To develop the little bit of fluff I get.

Is this going to be more light then the plant can use? Is CO2 going to be the answer?

I don’t want to waste hydro if I’m not going to see the return. I am proud of how efficient my set up operates for its production. And not needing a A/C to keep temps in check.

Thanks for any input.
 
Gonna sit in and take in this info just incase I go for a bigger tent. I would think that's a lot of wattage for a 3x3. Have you considered side lighting to get at and just under the screen? Don't know how much you leave under the skirt.. is it 70's style.. or new age? lol I'm freezing the larf I had on my 1st run to use for bubble hash after this next run.
 
HydroKid239 said:
Gonna sit in and take in this info just incase I go for a bigger tent. I would think that's a lot of wattage for a 3x3. Have you considered side lighting to get at and just under the screen? Don't know how much you leave under the skirt.. is it 70's style.. or new age? lol I'm freezing the larf I had on my 1st run to use for bubble hash after this next run.
Click to expand...
New age bud. Lol.
Lollipop up to the screen.

Canopy is usually 4”-8” thick. With some colas maybe hitting 12” high
 
Bookush34 said:
New age bud. Lol.
Lollipop up to the screen.

Canopy is usually 4”-8” thick. With some colas maybe hitting 12” high
Click to expand...
Ever ponder on having some light down bottom facing up at the base of the colas and whatever is at the screen? Could be the key to fattening up that fluffy shit while working with the lighting you have.
 
Bookush34 said:
... I have a 3x3 tent set up. I have a custom built air cooled 500watt Cob I built using vero29s from timber grow lights. I have a few years of running this set up and i can run it dialed right in. I grow in 5gal hempys with 100% perlite. Using a SCROG. I can pull 12-16oz depending on a few things.

My existing set up gives me a 55w/sqft print. It works good but still at the base of the screen I get some larff fluff. ...
Click to expand...

For QB and COB LED's, 55 w/sq. ft. is as high as you want to go. 108 w/sq. ft. is overkill.

I give my flowering girls 40 w /sq. ft. - and for this grow, I am trying the schwazzing method to see if that will turn that LARF down by the mesh into more dense bud. Starting Week 4 today and so far, so good.

Do you defoliate?
 
HydroKid239 said:
Ever ponder on having some light down bottom facing up at the base of the colas and whatever is at the screen? Could be the key to fattening up that fluffy shit while working with the lighting you have.
Click to expand...
I wonder how the plant would take to lights hitting the under side of the leaf?

Might get all the fan leaves twisting and facing down?
 
StareCase said:
For QB and COB LED's, 55 w/sq. ft. is as high as you want to go. 108 w/sq. ft. is overkill.

I give my flowering girls 40 w /sq. ft. - and for this grow, I am trying the schwazzing method to see if that will turn that LARF down by the mesh into more dense bud. Starting Week 4 today and so far, so good.

Do you defoliate?
Click to expand...
Yeah I defoliate lots.

How did you determine how much is too much? I don’t get any bleaching in my leaves until about 8-10”

I’ll have to look into that schwazzing
 
Bookush34 said:
Yeah I defoliate lots.

How did you determine how much is too much? I don’t get any bleaching in my leaves until about 8-10”

I’ll have to look into that schwazzing
Click to expand...
Well my HLG 135 boards turned down to 90 watts will fry my shit that close. They probably grew within 12-14 inches and they were getting fried.
 
Bookush34 said:
... Yeah I defoliate lots ... I’ll have to look into that schwazzing ...
Click to expand...
You remove quite a few large fans for schwazzing. It's aggressive - but it opens shit up down below.
Bookush34 said:
... How did you determine how much is too much? ...
Click to expand...
Read a bunch of articles and watch a bunch of videos to find out what you need - proper PPFD levels, spectrum, wattage - to get those good yields in your grow area.

Lots of that awesome lighting info came from this very RIU board.

Self medicate then self educate ... works for me
Bookush34 said:
... I don’t get any bleaching in my leaves until about 8-10 ...
Click to expand...
Man ... that is really close.
 
StareCase said:
You remove quite a few large fans for schwazzing. It's aggressive - but it opens shit up down below.

Man ... that is really close
Click to expand...

I would call my defoliation aggressive. I usually pluck at 1 week of flower and then again at 3 weeks ish.

I see bleaching at 10”. But can run at 16” with out issue.

Maybe I need a PAR meter and see how much room I have for adding light.
 
If your canopy is only 8-12 inches deep you aren’t lacking in light at your current wt/sqft. If you want to remove the larf at the bottom do it.

Instead of defoliating leaves that generate energy for the plant to grow, I would suggest PRUNING the lower bud sites that won’t ever develop.

When you remove leaves the plant directs energy to replacing them. By removing these lower sites you allow the plant to redirect growth towards the upper buds.
 
Your plant will tell you whats too much. Some strains like higher light levels than others. Generally speaking sativa leaning hybrids tend to like more light and indica leaning likes less light. That said, there are no hard and fast rules other than listen to your plants.

That said, 108 watts per sqft is just way too much. I don't know any strain that would like that much light. Once you go past 50 watts per sqft with quality LED you are definitely wasting energy and probably reducing yields 35 watts per sqft is really a good place to be, might push 40 or 45 at a strain that likes a lot of light but the returns on the additional wattage will be minimal.

Using more COB's driven softer will not only provide even spread of light but it will be more efficient. As the COB's age and output diminishes you can add a few more watts to compensate unless there is a newer and better LED out there to drool over.
 
i use a 400 watt HPS at about 12 inches over a three 5 gallon plant setup my first grow so far so good it is in soil tommorow will be their 4 week birthday
 
Thundercat said:
If your canopy is only 8-12 inches deep you aren’t lacking in light at your current wt/sqft. If you want to remove the larf at the bottom do it.

Instead of defoliating leaves that generate energy for the plant to grow, I would suggest PRUNING the lower bud sites that won’t ever develop.

When you remove leaves the plant directs energy to replacing them. By removing these lower sites you allow the plant to redirect growth towards the upper buds.
Click to expand...
I’ll agree to disagree on plucking fan leaves. In a indoor setting plucking is benifical. Outdoor the sun penetrates through same with a 1000watt De hps. But I find led lacks that deep penitrating power.

I pluck bud sites as well. But that’s just a easy answer to dealing with larff. I’m try to get my fluff to dence up.
 
T
Renfro said:
Your plant will tell you whats too much. Some strains like higher light levels than others. Generally speaking sativa leaning hybrids tend to like more light and indica leaning likes less light. That said, there are no hard and fast rules other than listen to your plants.

That said, 108 watts per sqft is just way too much. I don't know any strain that would like that much light. Once you go past 50 watts per sqft with quality LED you are definitely wasting energy and probably reducing yields 35 watts per sqft is really a good place to be, might push 40 or 45 at a strain that likes a lot of light but the returns on the additional wattage will be minimal.

Using more COB's driven softer will not only provide even spread of light but it will be more efficient. As the COB's age and output diminishes you can add a few more watts to compensate unless there is a newer and better LED out there to drool over.
Click to expand...
My vero29 hood has about 6 grows on it. The citizen1212 bars have 2 grows.
So not really old.

All are dimmable.
Maybe I should put the 1212’s in but dim them a fair bit. Slowly turn up till I see Negative effects?
 
Bookush34 said:
But I find led lacks that deep penitrating power.
Click to expand...
Penetrating power? Explain this. If light hits a leaf, it does not pass through. The law of inverse squares mathematically explains why we get lesser light readings as we get farther from a single point of light emission. That said, typically LED has multiple points of emission and this provides more angles of penetration and generally better penetration as this gets around blockage.

The sun is so powerful and so far away, it doesn't matter if we hold a light meter down by the ground or up by our head, the photons have traveled millions of miles, a few feet isn't making much difference even with atmosphere.
 
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