COCO COIR Light Distribution on a scrog question

[DarthBonk]

So this grow ive took the time to learn about lights and umols, etc as ive come to realise the light distances given by manufactures are only guidlelines and its better to measure the light yourself. this has made me realise that at the centre of the light the plant gets the most light while on the edges of the square meter under the light the umols can be half what the centre is getting (they show this in graphs a lot of the time when you buy lights but didnt realise it was literally halved). The question i have then is how do all you scrog users tackle this without supplemental lighting. I had an idea to essentially turn the scrog net into a cone so that the edges are closer to the light than the centre, with only a few inches diffference however so that the apical dominance isnt effected ( people say different things about apical dominace but from what ive gathered plants wont notice a cola being a couple inches above another). Any thoughts on this? My father says its already been done but havent seen anything about it online.
cheers in advance for any help or enlightment

 

[Wayzee]

Good question. Ive grown different styles and am currently scrogging under a 700w led bar light. I do have supplement lighting for this grow but have not used them before. I do think it's important for the plant to know where it's "head" is and to do this and looking at other peoples scrog set ups is to have your plant set up so the head of it is growing toward to centre of the light so it's receiving the most amount of light, this way even though the plant is horizontal its still thinking it needs to grow toward the light as it would naturally.. as for getting more even spread of ppfd across all colas once the canopy is flat that comes down to the type, size, height and quality of light. To get all buds finished to same point you can always stage harvest at the end, taking off ripe tops and leaving the rest for a week and then take them.
if I can keep all my colas within a couple of inches of each other I'll be jumping for joy.

 

[Allenpro]

Well you have stepped into a brighter and certainly more confusing world. Yes the LED light manufacturers exaggerate the actual flowering footprint sort of like breeders under estimate flowering times. Trust no one.
I use bar lights that are fairly true to their claims so I set the middle to just under the max required for flower and the corners as just under. Looking back I would have bought 6 smaller lights instead of 3 larger ones for the most even canopy I could get. lesson learned

 

[Bluey]

Bar style lights have a better spread than quantum style boards. I have both in my flower room and use height and spacing to even the light out. The higher and brighter the light typically the better the spread, especially with milar coated reflective walls.

I always grow with a flat canopy, except with autos, and measure the light across the canopy, not top of the buds. I aim for 900 to 1000PPFD on the canopy which is quite a bit higher on the buds, 30 to 40% with quantums and a bit less with bar style. Bar style has a larger sweet spot re distance from canopy..Quantums require a more precise setting with more adjustments but also are harder on the buds with higher risk of foxtailing.

Under canopy lighting at about 20% of that on top will give great results and allows you to go a bit easier on the plant from the top

 

[DarthBonk]

seems like supplemental lighting is the way to go. I also use quantum boards (telos 10 pros). i didnt take the spread into account until your post. Essentially the closer the light the tighter the spread which is really annoying considering you need to lower the lights during flower. Thats definitely contributing to the lower pffd at the edges of my scrog nets. Ill get some cheap supplemental lights for flower in future. In terms of under canopy lightimg is it really worth doing if i lollypop? i have virtually no under canopy nugs as i pull them all to the top or remove. There probably is still areas getting less light due to fans and stacking of buds, etc, as i type this i realise that even though im rigorous with my pruning it could only help and it doesnt need to be anything as expensive or powerful as my quantum boards. Cheers for opening my eyes

 

[Bluey]

I lollipop also. Under canopy lighting will give around a 10% to 20% increase in yields and you dont need anything fancy re the lighting....any light will just about do the trick as long as it's water resistant