Is this light burn?

CARmick93

Active Member
My plants are at the end of 6th week of flower, for weeks now I’ve been having problems with the leaves turning yellow, rusty and going crispy on the tips. I’ve tried everything to resolve this, at first I thought it was nute burn so flushed the plant and lowered the nutrients I then got deficiencies so raised the nutes back to normal. Ive used cal mag in case there was a defciency in this. Nothing seems to be working.
Then today I was having a look on a website and noticed a picture of extreme light burn and noticed it looked like what I was getting, so I was wondering if anyone could confirm this?
I’m using mars hydro 2000w led lights they are about 18” away from the tops of the plants, (apart from ones at the back which I ran out of room but so far they seem ok) not sure if this is the cause of the problems, this is as far away as I can get the lights. Any help much appreciated.
 

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CARmick93

Active Member
That’s what I was thinking, I’ve ordered a lux meter so I can see what it is and alter the light.
 

Jules1976

Well-Known Member
Next time might I suggest asking for advice when the problem first starts as if you leave it too long and loose everything do you have a dimmer if so turn them down for a few days see if any difference if you can't dim can you raise your light?
 

CARmick93

Active Member
Next time might I suggest asking for advice when the problem first starts as if you leave it too long and loose everything do you have a dimmer if so turn them down for a few days see if any difference if you can't dim can you raise your light?
I did on a previous post and some people suggested it was p defciency or mag issue so I upped the nutes and used cal mag but obviously didn’t work and yes there is a dimmer on the light I have turned it down about a third so will see if this makes a difference.
 

CARmick93

Active Member
What are you feeding, ppms, ph, etc?
I’m using biobizz bloom, alga mic and molasses and cal mag every other water. I ph the water to 6.5, I’ve never actually checked the ppm I read that since using organic nutes in organic soil there is no need to I have just been using half dose of nutes. I’m using plant magic soil supreme.
 

Week4@inCharge

Well-Known Member
I’m using biobizz bloom, alga mic and molasses and cal mag every other water. I ph the water to 6.5, I’ve never actually checked the ppm I read that since using organic nutes in organic soil there is no need to I have just been using half dose of nutes. I’m using plant magic soil supreme.
probably just light burn. Already mentioned..the ladies in the back (not directly under the light) look excellent. It's gonna be really hard to judge if dimming the lights will help, damage is done, no turning back on that. Just test the PPFD output for the next grow. You should still be good, this is weed after all..lol, how can you mess that up? At least your flowers look intact. Good luck.
 

CARmick93

Active Member
probably just light burn. Already mentioned..the ladies in the back (not directly under the light) look excellent. It's gonna be really hard to judge if dimming the lights will help, damage is done, no turning back on that. Just test the PPFD output for the next grow. You should still be good, this is weed after all..lol, how can you mess that up? At least your flowers look intact. Good luck.
Thanks for the reply, I’ve only been doing this for about a year now so still got a lot to learn, I never even thought about testing the lights before as they could damage the plants this much. I’ve ordered a lux meter so hopefully can get them set up right.
 

CARmick93

Active Member
"I always ph the water to 6,5"
Do you check ph after adding all your nutrients? Some nutrients will lower the ph of your water significantly so try checking ph after mixing up your feed.
Yes always add the nutrients first then check the ph and buffer up or down.
 

In4It789

Active Member
that looks a lot like the problems I had with my first ever grow a few months ago. It was Hydro and mine definitely had more problems than yours though. Ended up being a PH issue causing lockout combined with light burn… had my SF2000 about 15 inches from top at full power… I fixed the PH and upped the lights, then I cut off all of the dead growth. My buds still had a good week to go and they ended up swelling and turning quite happy just before harvest, so I lucked out! Here’s pics of the awful & then a snapshot of the final buds…I know they aren’t impressive but we all start somewhere right?! Looking forward to some updated pics!
 

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Week4@inCharge

Well-Known Member
that looks a lot like the problems I had with my first ever grow a few months ago. It was Hydro and mine definitely had more problems than yours though. Ended up being a PH issue causing lockout combined with light burn… had my SF2000 about 15 inches from top at full power… I fixed the PH and upped the lights, then I cut off all of the dead growth. My buds still had a good week to go and they ended up swelling and turning quite happy just before harvest, so I lucked out! Here’s pics of the awful & then a snapshot of the final buds…I know they aren’t impressive but we all start somewhere right?! Looking forward to some updated pics!
going through similar thing myself..seems to be a common thing, light burn and pH... stoked you got it under control, gives me hope. What did you do to fix your pH problem? Was it runoff you were checking?
 

CARmick93

Active Member
that looks a lot like the problems I had with my first ever grow a few months ago. It was Hydro and mine definitely had more problems than yours though. Ended up being a PH issue causing lockout combined with light burn… had my SF2000 about 15 inches from top at full power… I fixed the PH and upped the lights, then I cut off all of the dead growth. My buds still had a good week to go and they ended up swelling and turning quite happy just before harvest, so I lucked out! Here’s pics of the awful & then a snapshot of the final buds…I know they aren’t impressive but we all start somewhere right?! Looking forward to some updated pics!
I’m glad it worked out for you mate, your buds still look nice. I’m new to growing as well so still learning all the time, would love to start a hydro grow but don’t really have the space to do it as my set up is in my loft.

I think most of the buds on mine are pretty fucked a few have foxtailed with the light stress so will probablies make some hash with them but some look ok and still have a few weeks to go so fingers crossed.
 

Week4@inCharge

Well-Known Member
I’m glad it worked out for you mate, your buds still look nice. I’m new to growing as well so still learning all the time, would love to start a hydro grow but don’t really have the space to do it as my set up is in my loft.

I think most of the buds on mine are pretty fucked a few have foxtailed with the light stress so will probablies make some hash with them but some look ok and still have a few weeks to go so fingers crossed.
I still don't know what foxtails is ...
 
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