Leaf Burn - Not Sure Why

[BigOlBug]

These are 15 weeks old and in their 4th week of flower. Noticed the leaf tips turning yellow about two weeks ago. Doesn’t seem to be spreading as these pics are from today.

using General Hydro medium feed and flushing every 4th water. Coco coir and a Spider farmer light.

so, is is light burn or nutrient burn? - Thoughts?

[Ckbrew]

Nice looking grow. That is from the nutes. Some people push the nutes and use that tip burn as an indicator that they have maxed out the nutes and it is time to stop. At week 4 you should be reducing the grow formula and bosting the bloom formula. They look a little dark green indicating to much N, but the second pix shows both dark and light leaves. That may just be from the lighting in the pix. You should evaluate the color with your eye. How is the pH going in? I aim for 5.8 -6.0 in flower. I think you are good so long as the grow formula is cut way back, you are approaching the point to completely stop the grow formula and just run on calmag, micro, and bloom. Are you following the schedule from GWE? Carry on.

[BigOlBug]

Thanks Ckbrew!

I run 5.5 to 6 and I am using GH medium feed. Next week I’ll be cutting back severely on the nutes just like you said. So it looks like I’ll carry on the way I’m going. The dark leaves were definitely a lighting issue.

happy holidays!!!

[Allotrope1000]

Hi, Big...
I will second Ckbrew's comment. Looks like a little nute burn. I am one of those who feeds the plants until I see a tiny, brown leaf tip. Then back off the fertilizer a bit.

I think you'll be okay.

[BigOlBug]

Thanks for the assistance Allotrope1000!

[sc0rpi000]

Thanks Ckbrew!

I run 5.5 to 6 and I am using GH medium feed. Next week I’ll be cutting back severely on the nutes just like you said. So it looks like I’ll carry on the way I’m going. The dark leaves were definitely a lighting issue.

happy holidays!!!

looks good, would also just chill on the fertilizer for a minute!

[Bluey]

In flower in coco substrate I run a higher pH, 6.1 to 6.35 and a bit either side if I need. Average around 6.2ish. You'll work out what works best with your setup & grow