LED light 12 inches above canopy during flower?

Moflow said:

Just turn the power down to 80%, sorted!

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I’m measuring the % by PPFD meter I need to use max power to give the plants the amount of light they need

Fucked around trying my LST to lower the stretched girls in the back snapped a main cola off during the process just leaving them alone from here on out‍

cannabiscrusader said:

You've done everything you can then, aside from boosting the tent. Good on you being proactive

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Took it to another LST level and lost a main cola

Cousin Bo said:

Do you know the LUX reading? I have a couple plants that are about that close now and they seem happy even though some spots are getting close to 100,000 LUX.

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holy smokes bro the max i let my plants get is like 70k lux and i mean thats tops. if your using LED 100k lux is like 1700ppf :O

secretmicrogrow420 said:

holy smokes bro the max i let my plants get is like 70k lux and i mean thats tops. if your using LED 100k lux is like 1700ppf :O
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Lux to PPFD conversions?

The figures above are using a conversion factor of about 0.016 which is appropriate for a dedicated "flower" light that has a high proportion of red in the spectrum. If you're using that number for a grow light that's doesn't have a lot of red, using a factor that high will overstate the PPFD value, meaning that your plants are getting less light than calculated value.

The light saturation point for cannabis is 800 to 1000µmol in ambient CO2, meaning that a cannabis plant can process that level of photons without damage.

I've attached a copy of a PDF I put wrote then I was looking into using an lux meter to measure light for my grow.

cannabiscrusader said:

The leaf edges at the tops will begin to discolor. If you don't dim the lights at that point, water will continue to transpire from the leaf faster than the nutrients can be used. This leads to a buildup of nutrients that begin to burn the leaves.

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VPD drives transpiration; too many photons starts with "photo avoidance" and ends up with the physical destruction of leaf tissue.

When gas discharge lights were more common, "too much light" was due to the heat given off by the fixture plus the IR radiation which resulted in elevated temperatures on the leaf surface. The increased temperatures would drive up VPD which, in turn, would increase transpiration.

With LED's there is no increased IR/heat/VPD but you can still have too many photons hitting the leaves. The typical initial reaction is photo avoidance where the edges of the leaf curl ("tacoing") or by the leaf rotating around the petiole, so as to receive less light. If the light levels are not reduced, the plant tissue will be damaged.

coreywebster said:

Going against popular opinion, I'd say its fine because it's a bar light your not getting massive hotshots.

Mine are about 6" off the tops I think.

Personally though I'd bend all those plant gently out and tuck them.. lots of wasted space in that net and you can fill it by pulling them tops one way or another

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Exactly. Depends on genes too. I’ve had some go right through the light. Haha