Light burn?

Good morning

I am in day 30 of flower
DWC seedsman fem Jack Herer
Half dose of General hydroponics flora Trio

I believe I’m getting light burn the canopy is at a minimum of 20 inches and my lights are dimmed below 50% the symptoms are occurring up to 30 inches down. The symptoms are occurring extremely slowly.

lights- 3 vero 29 c no lens or reflectors roughly 240 watts built the fixture in 2017 and never used.

I am blown away by how powerful these things are or this stain is quite sensitive not sure.
What is my best option moving forward I’m out of height in the tent I know I can dim the lights more or I could bent the canopy?

Input much appreciated

Zoufs

Looks like nute burn,tips from to much N

How much are u feeding them, any additives

Cal mag and hydro guard. I had a nitrogen toxicity a couple weeks ago. tips of leaves folding down so I flushed with pH water for about four days. Then returned to half strength nutrients. Seemed to help.

I could’ve sworn it was from the lights.

I got to get a ppm meter on there I suppose.

How much nutes u feeding them

Half strength shouldn't burn them


And u don't really flush in dwc

put your hand above the plants and hold it there if it doesnt get real hot in 30 seconds its not your lights i keep a 600 watt metal halide 10 inches away and my plants love it

osowhom said:

put your hand above the plants and hold it there if it doesnt get real hot in 30 seconds its not your lights i keep a 600 watt metal halide 10 inches away and my plants love it

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Thats a good advice for a HID but not for leds, leds can give light burn with no heat on your hand as it is a light with no IR.

I agree with Bob, looks like nute burn on the tips. Try to measure ph and ec of the run off if your already on low nutes.
Light burn shouldnt happen 30" away from a 80w cob. Also the leaves are only affected on the tips, the rest is super green which doesnt look like led light burn.

Zoufs said:

Good morning

I am in day 30 of flower
DWC seedsman fem Jack Herer
Half dose of General hydroponics flora Trio

I believe I’m getting light burn the canopy is at a minimum of 20 inches and my lights are dimmed below 50% the symptoms are occurring up to 30 inches down. The symptoms are occurring extremely slowly.

lights- 3 vero 29 c no lens or reflectors roughly 240 watts built the fixture in 2017 and never used.

I am blown away by how powerful these things are or this stain is quite sensitive not sure.
What is my best option moving forward I’m out of height in the tent I know I can dim the lights more or I could bent the canopy?

Input much appreciated

Zoufs

Click to expand...

I wonder if you are under feeding them? I used to use the GH trio at half strength. When I switched to an HLG 600 Rspec in a 4x4 tent I ended up doubling the feed when they started developing the same yellow tips. Now I am using more than the GH feed chart states but hey are quite happy. This may not be your issue but I thought I would mention it since I had the same yellow tips the extra feed fixed them right up. Good luck.

It is interesting that it could be either high or low. The 10 gallon tub that has the issue has two plants. I have a single plant right next-door with no issues.
I will get a TDS meter on it this weekend I don’t have access to them daily is part of the problem.

Here are some photos from today along with my schedule.

Thanks again

Rocket Soul said:

Thats a good advice for a HID but not for leds, leds can give light burn with no heat on your hand as it is a light with no IR.

I agree with Bob, looks like nute burn on the tips. Try to measure ph and ec of the run off if your already on low nutes.
Light burn shouldnt happen 30" away from a 80w cob. Also the leaves are only affected on the tips, the rest is super green which doesnt look like led light burn.

Click to expand...

sorry didnt realize he was running led scratch that thought i just lowered my mh to 9 inches lol 600 watts they are praying to the light and loving it

I don't see anyone burning their leaves with LED lights 20-inches away, and definitely not 30-inches into the canopy.

I use Vero's @ 75 watts/cob on my 4 light fixture.
I typically run them at 12-18" above the canopy at full power.
I don't think that you have light burn-tweak your nute mix a bit to reduce N and see what it does.
It should be able to handle full power now.

GBAUTO said:

I use Vero's @ 75 watts/cob on my 4 light fixture.
I typically run them at 12-18" above the canopy at full power.
I don't think that you have light burn-tweak your nute mix a bit to reduce N and see what it does.
It should be able to handle full power now.

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Glad I found someone with the same lights I was under the impression I would fry them.
Tested water yesterday 1425 ppm the burn has seemed to halt over the past few days. It appears on the right track?

Also what happened in the world of LED, are Quantum boards the new rage? I built my fixture four years ago when cobs were hot stuff and finally using it. Been out of touch

Thanks again

Zoufs said:

Tested water yesterday 1425 ppm the burn has seemed to halt over the past few days.

Click to expand...

2.85 EC? Seems pretty high to me.

Just recently I was told to drop in about 10% would that be an appropriate start?