Built new light---need help with light burn (I think)

Autos. Seedsman Critical 2.0 and Zkittles plus a Fast Buds Lemon Pie 3x3
GH Flora Trio, Cal Mag, and using up Terpinator. Just raised ppm from 625 to 780 two days ago. Coco/Perlite 80/20.

I built a few cob leds about four years ago and have had a lot of success with them. Saw these https://www.amazon.com/gp/slredirect/picassoRedirect.html/ref=pa_sp_atf_aps_sr_pg1_1?ie=UTF8&adId=A06355582WJNKK4LCZPW8&qualifier=1673751008&id=2082404871329303&widgetName=sp_atf&url=/KQO-Boards-Samsung-Spectrum-Lighting/dp/B08JXBCRCP/ref=sr_1_1_sspa?crid=2H60QFSBSK43J&keywords=kqo+120w+grow+light&qid=1673751008&sprefix=kqo+120w+grow+light%2Caps%2C111&sr=8-1-spons&psc=1 and bought two of them (total of four boards) and built myself a new light.

The light draws up to 520w from the wall and are dimmable. I got carried away and burned the hell out of the top of my plants---or 90% sure I did. I was trying to hang my light low as possible and run them softer than higher up and turned up. This was new to me as I have always keep the cob light 18"-20". I was trying to keep board at 12". Every four days I would increase the wattage in 15-20w increments keeping my eye out for light stress. I pushed it up to 315w a few day before week 3 of flower and the next morning severe drooping and leaf curling on the Zkittles and Lemon Pie. This was a week before the pics. I raised light to 16" cut back to 290w. The quit drooping that day and leaves were praying again the next. Three days pass and they were looking worse with yellowing and some brown spots appearing. I raised the light again to 16" (the Zkittles and Lemon Pie still stretching) and dropped the wattage 20 more to 270w. Its now three days later and they are twice as bad as they were last week. Today is first day of fourth week flower and the light is 14" away from highest cola. I could probably squeeze 4-5 more inches of height immediately but have a new tent coming in tomorrow and I plan to hang it high as possible.

What I need insight on is the led boards and wattage through flowering and heights. Do you guys like to keep light up high and turned up and let the plants grow up into them or the low height way? In my defense they didnt show any stress until that one morning. I have been reading up a lot on lumens, ppfd, and DLI. I'm not sure if the Photone app I have been playing with is truly accurate but I do know that it is consistant with readings across the board. Reading forums and watching social media its supposed to be a good lux indicator. Not sure if the boards are complete crap or not with their efficacy/efficiency ?? but the highest I got my lux was 48,000. My understanding is 50,000-75,000 is ideal for flowering. Right now my lux is 30,000 at highest point...

Is it normal once you burn the tops for them to look worse or did I not lower lights and raise height enough. Was I nuts on that many watts that close third week of flower. I quit recording my watts and distances a while ago just kind of eyeballed it so I didn't have a reference. The tops leaves of Zkittles are starting to claw now.
Do I keep turning it down? The furthest I will be able to get the light from the plant is 19". I dont think my lux reading were wrong because the ppfd and DLI were going down about the same rate I could tell. I'm tired of writing... Stressed about trying to flower with only 30,000 lumens at 270w. Any feedback will be greatly appreciated

I do not see any sign of light burn.

30k lux in flower is low, 45k - 65k lux is recommended.

Good luck

I have 2 boards in my 3x3 running at 160 a piece right now and keep them around 20/24" above the plants.
You should be able to keep yours closer running 4 at the same total wattage. Dont think your issue is light related.

Are you PH'ing your feeds, watering with a good amount of runoff, and keeping that coco moist?

I have been growing in coco a while. It's easy and forgiving to me. 20% runoff, don't let top completely dry out, 5.8. Only the tops of the plants and all three show same symptoms. Clawing, lightening, and some brown spots appearing is why I cant see what else it could be and I am at a loss at what to do.

I don't see light burn. I see a couple leafs that look warm but not light burn

What light were you running previously?
Just like going from indoor to outdoor you may have to harden them off

They have been under the new light for three weeks. Up to the first week of flower I was using my homemade COB led light at 220w. I did increase my wattage 100w within 3 weeks with those new boards 12-14" from tops. My pics dont do the color difference of the top leaves close to the light and the ones below. My temps and humidity have been pretty much spot on for a while too

How often are you fertigating per day? Rather than raise the EC, I would feed at 1 to 1.2 EC base nutes (drop calmag and terpinator) at least twice per day to runoff, and try raising the PH to 6.3 to see if it makes a difference. If you still need more Mg after a week or so looking at new growth, add a small amount of Epsom salts.

They are all on their own schedule because of their sizes and me waiting until I feel they need water by look and weight. Nutes every time I feed with 20% plus runoff. I'm with you on stopping terpinator. Used it last grow and have no issue but really couldn't tell if it did anything. Had a lot left. I am skeptical about stopping calmag. Every time I even tried to back off with it in coco trying to save money would cause deficiencies real quick. So you think raising base nutes and stopping calcium will help? Thats the way I think I understand what you are saying. The epsom for mg?

breedwheel said:

They are all on their own schedule because of their sizes and me waiting until I feel they need water by look and weight. Nutes every time I feed with 20% plus runoff. I'm with you on stopping terpinator. Used it last grow and have no issue but really couldn't tell if it did anything. Had a lot left. I am skeptical about stopping calmag. Every time I even tried to back off with it in coco trying to save money would cause deficiencies real quick. So you think raising base nutes and stopping calcium will help? Thats the way I think I understand what you are saying. The epsom for mg?

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When growing in coco I disregarded by weight watering
Best results were achieved by setting a schedule to water twice a day always feeding
Coco done right is hydro

I feel hydro is just using liquid nutes instead of soil--in whatever medium your can grow in like that. I have never keep my pots saturated all the time but never let the roots come close to drying out. I know a lot of people keep their coco totally wet all the time but I never have. Guess it wouldn't hurt to try but I'm stubborn because I have had good results in the past. I couldn't afford to wash too many nutes down the drain in my early grows

breedwheel said:

I feel hydro is just using liquid nutes instead of soil--in whatever medium your can grow in like that. I have never keep my pots saturated all the time but never let the roots come close to drying out. I know a lot of people keep their coco totally wet all the time but I never have. Guess it wouldn't hurt to try but I'm stubborn because I have had good results in the past. I couldn't afford to wash too many nutes down the drain in my early grows

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would you let a dwc sit empty?

Why don't I just submerse my pots into water then?

breedwheel said:

I feel hydro is just using liquid nutes instead of soil--in whatever medium your can grow in like that. I have never keep my pots saturated all the time but never let the roots come close to drying out. I know a lot of people keep their coco totally wet all the time but I never have. Guess it wouldn't hurt to try but I'm stubborn because I have had good results in the past. I couldn't afford to wash too many nutes down the drain in my early grows

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multiple daily feeds at a low EC with little to no runoff may mean less nutes rather than more. saturated coco has an ideal air/water ratio, so any dryback period is a period consisting of sub-optimal circumstances. I can't say the same about peat, though.