Jacks 321 in Flower - nute burn

I’m currently running Jacks 321 and in the 4-5th week of flower. I recently started to notice some nutrient burn at the tips of a couple of my plants. I have been pretty conservative on jacks typically feeding 1/2 to 2/3rds the recommended dose.

Question is, should I be backing an additional 1/2 of the dose of Part B to reduce the amount of nitrogen at this point in flower? My PPMs in runoff were around 1100, so it didn’t seem real heavy with nutrients.

Once I seen the yellow /brown tips, I watered with only PH water to reduce the amount of nutes

I was planning to cut back the Part B by 1/2 but looking for suggestions… thanks again for all the support.


I would not reduce the feed. My jacks is usually about 1100ppm fed daily. Just keep a eye on the runoff numbers. Picture would help, and light burn can cause yellowing on the tips just a fyi. Usually nitro burn has the brownish/orange tips.


I would never, i repeat never feed water only in coco if thats what u are in (unless its the end flush). It will mess up the cation exchange rate of the coco.


The tips are shown in the photo below…. I was only around 550 - 600 ppfd when getting this burn issue. I am running in soil.


Looks nice and healthy , I don’t worry too much about The tiny tip burn. :+1:


I also use Jacks 321, and like it. Before this I used Mills Nutrients, and with Mills is very easy to adjust the nutrient levels. I would be very happy during veg with big fan leaves without any burnt tips. But during flowering the sugar leaves would end up looking like yours. Learned not to worry about it. I think if you withheld enough nutrients to prevent this the bud quality would suffer. Of course the brown tips maybe caused by the drier conditions during flowering.


What’s your ph going in and out?

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If your running in soil and getting tip burn its time to flush and refeed.

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