First time grower, need help identifying the cause of leaf tip burn

Do you have any run off readings of your ph and ppm. That might help narrow down or at least eliminate a few possibilities, and also what is you ph and ppm reading going in ? More info the better

Last watering I used a tea so I didn’t have run off to measure this was 2 days ago. I use to water at 6.5ph but now I lowered the ph to 6.0 on my next watering today or tomorrow.
I haven’t fed the plants anything other then the dry amendments that were mixed at the beginning of grow and two teas.

Only two out of 4 plants are showing these symptoms. One us a Bruce Banner and Girl Scout Cookies.



This is from your first post on 1/7. Is this still so or did you water to runoff and measure PH & PPM?
These are photos of magnesium deficiency from a Drcannabis article regarding same.


Recommend searching for the article and giving it a read. It includes discussion about importance of PH and the use of Epsom salt to correct. Also the use of a very common supplement Cal-Mag.
Growweedeasy also has an excellent article with many of the same points.

I suspect the nutrients given lack the requisite magnesium or PH is preventing its uptake.

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I have cal mag coming in today and I will water tonight to run off and measure.

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Yeah it is one of those items you have to have in the medicine cabinet. Follow the directions and keep up the ph & PPM numbers to see if they move or are stable.

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Update: I got my cal mag last night and added it to the water. I had 5 gallons of water total once I divided the water for each plant and watered it I still didn’t have enough water for any kind of run off. Today I filled 2 5 gallon buckets for my next watering so I can make sure I have enough for 10% run off. I guess I’m way of when it comes to the amount of water I should be using.

I do have a soil PH tester which I used to test my medium and after watering my coco PH is between 6 and 6.2.

After a few days of reading I’m a 100% sure this is a iron deficiency most likely caused by nutrient lockout due to high ph watering.

Up until the last watering I did my ph has been 6.5 now I took it down to 6.0 and my last watering I did about 15% run off. When I measured the ph of run off on last watering it was 5.8 but when I tried to measure the Ppm my meter would just give me lines so I assume this meter goes up to a 1000 and my ppm was higher.
I have ordered a new ppm meter and should get it before next watering.

I made a cal-mag foliar spray and started misting the leaves hoping this will help with the iron deficiency until I get the lockout sorted.

My watering from now on will have at least 10% run off and I will not add any nutrients for next two watering.

Does this sound like a good plan or am I way off?