Burning from the inside out... literally.

[Week4Bytch]

What's up guys, got a little riddle hear going on and wondering what it could be. My initial thought is Phosphorous Deficiency. Growing out of Fox Farm soil, added dry amendments topping with an occasional liquid kelp feed. Soils pH is now at 6.3 (just measured her) I also moved the fan away from these guys and pointed it 5 inches above these ladies, it was at about an inch or two above them. (wind burn?) I water half a gallon every third day to the 7 gallon pots. (sometimes every 2nd day) Any ideas as to what's causing the burn from the inside to outside?

 

[Observationist]

Looks nitro deficient to me as well, and those buds have a bit to go to fully form

 

[Week4Bytch]

Looks nitro deficient to me as well, and those buds have a bit to go to fully form

Yes, they got about 3 or 4 weeks to go, ok, I can fix a malnutritioned plant. I was just feeding them a little phosphorus and potassium. I decided to use my yellow bottled flower nutes A & B today , the A bottle has some nitro in it, Just caught me by surprise when I opened the tent today, i thought for a second, do I feed or not? I went ahead and feed them, they look hungry. ph checks out.

 

[mysticepipedon]

Have they gotten a lot of calcium, by any chance?

Sorry, I have calcium-caused lockout on the brain. I've had this symptom and mine stemmed from an overabundance of calcium. I think it's a P deficiency symptom, but I don't know for sure.

 

[Week4Bytch]

Have they gotten a lot of calcium, by any chance?

Sorry, I have calcium-caused lockout on the brain. I've had this symptom and mine stemmed from an overabundance of calcium. I think it's a P deficiency symptom, but I don't know for sure.

Yes, I think I am going through an overabundance of calcium. My tap water is at about 350 ppm (half of that calcium carbonate) A calcium build up will cause a phosphorus and magnesium lockout. If it gets any worse I'm gonna top dress with some charcoal, organics, when you get it right it's beautiful, but get it wrong..slowest train wreck ever. Hard to flush an organic soil grow.

 

[mysticepipedon]

Yes, I think I am going through an overabundance of calcium. My tap water is at about 350 ppm (half of that calcium carbonate) A calcium build up will cause a phosphorus and magnesium lockout. If it gets any worse I'm gonna top dress with some charcoal, organics, when you get it right it's beautiful, but get it wrong..slowest train wreck ever. Hard to flush an organic soil grow.

Make sure anything you feed has zero calcium. I give mine epsom salts, every other week.

Good to see you know the cause. If you give them nitrogen, they'll just hook their leaves.

Phosphorus should help immobilize a lot of the free calcium in the soil solution. Upping the dose on that might be beneficial.

 

[Week4Bytch]

Make sure anything you feed has zero calcium. I give mine epsom salts, every other week.

Good to see you know the cause. If you give them nitrogen, they'll just hook their leaves.

Phosphorus should help immobilize a lot of the free calcium in the soil solution. Upping the dose on that might be beneficial.

I've been going through this for 2 years and it's come full circle this grow/round. An article on Maximum Yield (January issue) "Cal Mag" brought so much light into my issues.

"Experienced growers know Day 30 is right around the time when plants stop getting taller and begin to focus on flower formation. It’s a big shift in the morphology of the plant and mineral behaviors change accordingly. I’m here to contend this is the point in the cycle when pumping cal/mag into the plants becomes a fool’s errand. Several nutrient geeks out there might be thinking at this point, “But nine percent and 2.5 percent isn’t too much. The plants are fine with it.” I had several colleagues tell me exactly that when I began to sound the alarm about calcium excess a few years ago. Besides the lack of historical data for cannabis mineral uptake, maybe growers and nutrient designers believed high cal/mag in late flower was okay because they’d seen some cultivars perform well with it. It is true that the problems caused by high calcium are not noticeable in all cultivars. It occurred to me that maybe the most user-friendly cultivars out there, such as Blue Dream or Gorilla Glue, could have become so legendary, in part, because they aren’t sensitive to high calcium. If most growers overdose plants on calcium, then the least sensitive cultivars would surely become industry favourites, right? For 50-plus percent of all cultivars, however, high calcium after Day 30 is a yield killer. I’m throwing down the gauntlet on this one. And I’ll go one step further with my assertions — that high calcium in dried flower material is a leading cause of bad smokeability (harshness) in the final product. This second claim of mine is complicated by the fact other minerals excessively present at harvest time can also cause smokeability problems, but I believe calcium is the primary cause of this problem because of how commonly it ends up very high in plants at harvest time relative to other minerals, based on what I’ve seen in hundreds of leaf tissue analysis results over the years

As for ideal Ca levels, in water culture settings, assuming the use of distilled or RO water, I recommend about 40ppm of Ca after Day 30 of the flowering cycle. For any soil-like media that is calcium buffered, I recommend 0ppm of additional Ca after Day 30 of flower. As for leaf tissue quantities, the goal is to end up with 4-5 percent Ca in the leaf tissue during the last few weeks of harvest. If you have more than that, you’ve likely dented your yields and smoke quality in most cultivars. In cases where I can’t remove calcium from fortified soil, I’ve still sometimes ended up with far too much Ca in the plants at harvest time, even using RO water and a fertilizer formula containing zero calcium. I have found that soil companies are generally not consistent or careful with the amount of calcium they add to their soils, not even the big well known national and international manufacturers. I can only assume it’s because they aren’t aware of the potentially negative consequences of high Ca, and their main priority is stabilizing pH more-so than supplying an ideal amount of calcium for a particular crop type"

So yes...know your soil, know your water source, know your nutrient line up.