What do you think I’m missing?

3 plants skittlz glue I think, probably about week 6ish of flower. Rusty spots started showing up slowly 7-10 days ago. Progressively getting worse.

Growing in coco, auto watering 4 times a day Using half ro, half tap water, feeding remo cal mag, bloom and micro. Usually 1000ppm give or take a 100.
Generally I’d say calcium but with half tap water high in calcium, and added cal mag seems unlikely. PH between 5.7-6.1.

I’m going with potassium. Are the leaves kinda thick or corse, break when you bend the fingers?

93OG said:

I’m going with potassium. Are the leaves kinda thick or corse, break when you bend the fingers?

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The ones that are the worst are pretty brittle where it’s bad yes. You’re thinking they need more potassium?

I’ve been pretty heavy on the nute mixtures. Seems too late to bring them back. One plant is worse than the others.

I almost think Ca deficiency, bugs, or lockout.

PadawanWarrior said:

I almost think Ca deficiency, bugs, or lockout.

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I really don’t think it’s bugs or calcium. I had the thought it could be lockout.

I’ve had the same def in late flower. Chased it with cal mag with no improvement. Some time after I saw an article somewhere that said it’s potassium so I upped it for the next cycle and it didn’t happen nearly as bad. I suppose it could be both since k didn’t 100% fix it. Probably not worth going down the rabbit hole so late in flower unless it’s a long strain

93OG said:

I’ve had the same def in late flower. Chased it with cal mag with no improvement. Some time after I saw an article somewhere that said it’s potassium so I upped it for the next cycle and it didn’t happen nearly as bad. I suppose it could be both since k didn’t 100% fix it. Probably not worth going down the rabbit hole so late in flower unless it’s a long strain

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Yeah I’ve come to the conclusion that it is what it is when you run into an issue this late in flower. Can’t really fix it, just try to figure out a way to keep it from getting worse. I ran into a nutrient issue last grow also.
Still trying to dial it in during flower. Veg is very pain free.
the humidity is also very low through winter due to the furnace running. Probably doesn’t help.
Might swap nutrient lines once these remo jugs are used up.

Magnesium and Phosphorous issues.

Water soluable Calcium Phosphate.... should solve your problem relatively quickly: