Light height question.

[farmingfisherman]

Just raised my lights and in order to get the same readings for light output at the canopy I had to increase the watts a fair bit. The numbers at the canopy are now nearly identical to what they were before raising. As long as the numbers are the same the plants should be okay, right?

Thanks

 

[Billy the Mountain]

Same meter, same reading = same intensity

If it was good at "x" before, it'll be good at "x" after raising the light.

 

[HydoDan]

Yep, I use a lux meter and thats how I do it..

 

[farmingfisherman]

Thanks gentlemen, always nice to have others input. Flipping to 12/12 tonight so thought raising the lights ahead of the stretch might not be a bad idea.

 

[con1ey]

I literally just wrote a post on light height and Daily Light Integral. Check it out https://www.rollitup.org/t/photoperiod-blueberry-gsc.1081389/post-17174381

 

[Comparator]

Just raised my lights and in order to get the same readings for light output at the canopy I had to increase the watts a fair bit. The numbers at the canopy are now nearly identical to what they were before raising. As long as the numbers are the same the plants should be okay, right?

Thanks

Your plants should be doing better with the added distance. As long as the ppfd is not to high for to long.

 

[Delps8]

Yes and, if your canopy doesn't fill the grow space completely, it could work out better.

A photon is a photon is a photon. They're all the same whether it's from a candle or from the big flaming ball of gas in the sky or from a Bic lighter at a concert. The only difference distance makes is that the photon took longer to hit the plant.

What is different is that, by raising an LED grow light, the photons have the opportunity to bounce off of the walls of the grow environment and, if you don't have a full canopy, that a can help get light to below the canopy. As best I can figure out that's the idea behind the marketing term "penetration" (the percentage of photons absorbed by a leaf is so high that no usable PAR can reach below the canopy unless there is a hole in the canopy).