Do my plants have a sun burn?

[chillbro]

I started flowering these plants about 1 1/2 weeks ago and when I switched the cycle I swapped out a 400 hps for a 1000 hps. It seemed like 3 of the plants in the back row seem a little stressed out. The sun leaves edges started curling up and now there is yellowing/browning spots along the edges. When I watered for the first time after the switch I gave them their first feeding. Fox Farm big bud and tiger bloom at 75% recommended feeding. I'm thinking this is just shock from the increase of light however the light is a good 2 feet off the plants. What do you think, sun burn or nute burn?
Peace,
Chillbro

 

[sungoddess]

Are they all the same strain? And the leaves that look sick - is it just on the top, or on the undergrowth too?

 

[chillbro]

Yes, they are all the same strain. B13 (Bubba and G13 cross) so I was told. I really like it though. Very healthy so far, except for this. It appears to be just on the top of the leaf. Thank you for trying to help.

 

[sungoddess]

Yes, they are all the same strain. B13 (Bubba and G13 cross) so I was told. I really like it though. Very healthy so far, except for this. It appears to be just on the top of the leaf. Thank you for trying to help.

My best educated guess would be that it's not the feeding then. If it was, it would show up on the undergrowth & not just the top (but I'm still learning). When we've had issues with nutrients, etc, it shows up everywhere, not just on top. And just a note - when you grow different strains, they will often show up with their own unique issues.

I'm still learning a lot & can't say a lot about lights, but maybe someone else will see this & chime in. GL

Have you tried using the search feature in the forum? I find that very useful.

 

[chillbro]

Thank you very much for your input, SG. That makes sense about nute burn affecting the entire leaf and not just the top.

Thanks again and good luck to you!

 

[Steve McStoferson]

My bet would be on the light. If it isn't spreading, it was probably due to the switch to the bigger light. If it continues, just back the light off a bit until they get used to it, then you can lower it bit by bit until you reach optimum height.