Do you lower DLI in final weeks?

[Badfinger]

Hi AFNer's
On the Photone website they have a chart pertaining to DLI over a 15 week grow with autoflowers. It shows lowering the DLI the last few weeks. I never heard of this, is this the norm, and I was just in the dark about it. Or is it just an opinion.

 

[Talonxracer]

Hi AFNer's
On the Photone website they have a chart pertaining to DLI over a 15 week grow with autoflowers. It shows lowering the DLI the last few weeks. I never heard of this, is this the norm, and I was just in the dark about it. Or is it just an opinion.

View attachment 1504142

That would follow what nature does in northern latitudes where Ruderalis originates from. I have a solar spectrograph for 60* north encompassing the entire summer and it looks very similar to that graph.

 

[Lil Dab]

I never heard of this, is this the norm, and I was just in the dark about it. Or is it just an opinion.

I have heard of it can't remember where atm but will look around and also seem to notice it in my plants. Near the end of most my grows seems the plants get light or heat stressed



Found this chart over at ILGM

 

[Mañ'O'Green]

I have indeed seen these studies but I do not dim in late flower. Maybe I should? or Length of day or both?

 

[Drownomatic]

Yes I lower the DLI, but I do it by raising the light.

I'll explain why:

As the mains get taller, and closer to the light the DLI at their top, and at the lower buds becomes quite a bit different. For this reason, I raise the light higher, and turn the dimmer up to maintain the correct reading.

As you raise the light more, the ratio of distance between light/top and light/bottom becomes more even, so there is much less difference in the fall off vs distance squared.

In the past, I've over lit the top of the colas trying to get enough light to the lower buds.

 

[Talonxracer]

Yes I lower the DLI, but I do it by raising the light.

I'll explain why:

As the mains get taller, and closer to the light the DLI at their top, and at the lower buds becomes quite a bit different. For this reason, I raise the light higher, and turn the dimmer up to maintain the correct reading.

As you raise the light more, the ratio of distance between light/top and light/bottom becomes more even, so there is much less difference in the fall off vs distance squared.

In the past, I've over lit the top of the colas trying to get enough light to the lower buds.

I raise the lights and turn them down, but by that time I have already installed my side lighting led strips for the lower buds to get their portion of light.

 

[Badfinger]

I think the only way I could follow this chart, is if I was constantly growing the same strain. And had a good idea how long the grow will last.
Since I have never grown the same strain twice, it would be difficult for me personally to know when to start the 3 week light reduction at the end of the grow.

 

[Talonxracer]

That is usually easy enough to figure out, in my experience you have approx three weeks left when the pistils change color.

 

[PeaceLove&Buds]

I raise the lights and turn them down, but by that time I have already installed my side lighting led strips for the lower buds to get their portion of light.

Can you please recommend which strip lights to use? And where do you place them?

 

[Talonxracer]

Here is where I get them, https://growdaddyleds.com/collections/frontpage
Also you can find them on ebay.

I usually hang them vertically in the tent corners, they can also be horizontal as well.