Nutrient Burn or Deficiency?

I am looking for some insight as to what the issue may be.

Current nutrients are mixed in RO water:

2 grams Jacks Hydro
2 grams Magnesium Sulfate (Epsom)
1.2 grams MKP
2.7 grams Calcium Nitrate

The plants are watered within 15 minutes of the lights coming on and on Day 31 of flower under 135 watts. Temps are mid 80s and humidity percentage in the mid 60s

Any idea of your EC when you feed? Possible phosphorus deficiency.

I am able to measure PPM with a TDS tester and I get a reading of 660 and when I convert to EC I get 1.32

Begging for potassium! You're in mid flower, and by the time it burns like that, the deficiency has been there a few weeks. Starts with slight paling at the edges of the leaf first.

So how do I resolve this issue?

xg43x said:

So how do I resolve this issue?

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Im not familiar with what you are feeding, and in powder form no less..i wouldn't know how much you should increase what you are giving, but from those pics and the ppm of your feed, it seems you should increase the amount of potassium going in, as it appears it's a deficiency, rather than a lockout issue. Do you see other leaves starting to pale at the margins as well? Once burnt in that way, it means that was an issue weeks before and has gone necrotic, if other leaves are not starting to get pale at the edges in that way, or the ones that are burnt are not getting further burnt (the burning moves inwards from tips and edges), then perhaps you fixed it along the way, but if you see symptoms spreading or getting worse...add more potassium! It's what the plant uses most, and at your stage, she needs it at the highest levels from week 2-5 of flower (indica, 7 week strain)!

Also forgot to note that the two tall plants are less than 4" from the Bridgelux EB LED strips. The brown tips don't really show on the new growth.

However, I did notice that some pistils are turning orange? Which would fall in line to what you are saying about a possible potssium deficiency.

xg43x said:

Also forgot to note that the two tall plants are less than 4" from the Bridgelux EB LED strips. The brown tips don't really show on the new growth.

However, I did notice that some pistils are turning orange? Which would fall in line to what you are saying about a possible potssium deficiency.

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I haven't used led strips, but last i saw, they are like christmas lights aren't they? I think they can touch those lights..the issue is not light bleaching at all! As for the pistils turning orange, that isn't a potassium issue, that's how pistils mature on the buds and will turn orange in the last trimester of the grow.

I use Jack's 3 2 1 just like you. From my experience, you're using too much Epsom and CalNitrate, especially at this point in the plant's life. The added MKP should address what Blitz35 is suggesting. Remember it's called Jacks 3 2 1 for a reason...your parts should be proportionally based off this ratio ie 3 Parts Base A, 2 Parts CalNitrate, 1 Part Epsom (Mg). So as an example if you're using 2g of Jacks Base, you should in general be using @ 1.3 g of CalNitrate and @ .6 g of Epsom. Again, going off my own experience only, pushing too far out of this ratio (3 2 1) and I begin to experience issues. Hope this helps.