Hello all, I'm seeing discoloration of leaves on one of my girls and I'm struggling to identify/correct the issue. I first noticed a deep rust color on new growth which I assumed was a calcium deficiency but I am hoping for some advice.
Setup info:
White Widow Auto (Flower started 10/22)
Spider Farmer SF4000 LED
Fox Farm soil
Fox Farm nutes (every other feeding)
CalMag (every other feeding)
PK Booster
Humidity in 40 to 50% range
Temperature between 70 - 82
When I noticed the discoloration I flushed, 4 days later I fed CalMag and tested RO.
PPM 1161
PH 6.0
Next feeding 3 days later:
PPM 890
PH 5.9
Last feeding I sprinkled a small amount of lime on the soil in hopes of bringing the PH up and haven't tested since then.
I also added a dose of PK booster as I have noticed some spotting on bottom leaves.
I would appreciate opinions on cause and where to go from here.
Thanks in advance..

Looks a lot like light burn. What is the light distance from the top of the plants?
Is the damage just on the top of the plant?
The light is 19" from the canopy.
Here is a pic that shows discoloration at the bottom of the plant.
19" is very close for the SF4000 since dead-center number is approximately 1400 PPFD (according to their PAR chart. Even their 22" measurement is 1197 PPFD. I'm pretty sure most run it at 24" from the top of the plants when in flowering. I personally aim for 600-900 PPFD in flowering. I think that picture shows a separate issue. That kind of looks like old damage from over-watering?
@Mr. Grow It you said it looks like old damage what makes you think thay the color of the damage? Just picking your brain lol
@Brandon Well he's showing a leaf on the lower part of plant, and when chronically overwatering, the lower leaves are impacted first. Once damaged, they don't get better; often they just slowly get worse. It just kind of looks like that in my opinion. That's just my guess; I could be wrong.
What week of Flowering are you in? I’d move the light up if it was me I burned my first run to a crisp I was also thinking it was a Deficiency
Your ph is a lil low but I wouldn’t think it would do that and your ppm doesn’t seam to be all that high to burn your plants like that
6th week of flower. I was able to raise the light to 26" which is the max in the environment. I will cut back on watering & post updates if things change. Thanks for the advice, it's appreciated.
You can also do LST if you still getting burns after a couple days or if your plants are still growing