Bet you haven't seen this one before

Been growing since it became legal here in Canada since 2017. Never have I come across this problem. Currently growing 4 clones of Permanent Maker, gifts of origin unknown and one of my all time favs Cali OG Kush Haze by CKS. As you can see in the pics, the clones (one in each corner) are all showing signs for stress. Either PH fluctuation or light/heat stress I think (reference Grow Weed Easy). The Cali in the center, absolutely perfect, not a blemish on a single leaf. All growing in the same environment, medium, same dry organic nutes, PH etc. Given the fact that the one is totally healthy, I can't figure out what's going on? My last grow had a similar circumstance but different issue. I had 3 clones (Mac Donuts) that all developed white powdery mildew and the Cali OG Kush that was in the same tent showed no sign of it ever.

Is this possible that some strains are overly fragile due to too much cross breeding?

Any thoughts out there?

IMO it's either potassium or magnesium at a glance.
You're feeding them, so question is, why?
Maybe you just went a bit heavy handed on the dry nutes and they're a bit locked out?

BongerChonger said:

IMO it's either potassium or magnesium at a glance.
You're feeding them, so question is, why?
Maybe you just went a bit heavy handed on the dry nutes and they're a bit locked out?

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At this point, I'll try anything. Next watering, I'll give it a bit of a flush. See if I can reset things. Why though is the one plant from seed perfectly fine?

Vinny.ca said:

At this point, I'll try anything. Next watering, I'll give it a bit of a flush. See if I can reset things. Why though is the one plant from seed perfectly fine?

Click to expand...

not all plants have the same intakes, even same seed gentics, i grow a bunch of different things, one plant will love great one next to it needs a little more or a little less