jumpincactus said:

You might also want to check on your water sources alkalinity as well, because the alkalinity of your water will also factor in on your ph levels. Alkalinity doesn't seem to be discussed much and it is certainly a player in the whole water chemistry thing. Your Kh levels have a direct correlation to the buffering capacity of your water/ medium.

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Can’t find a kit locally, may have to wait till I get to a bigger town, ha. But, I’ve looked at my latest county and municipal water reports and the water runs around 100ppm Total Alkalinity. It’s a little on the hard side. Apparently softening water results in the loss of calcium and magnesium, and I see no deficiencies in either. The 100ppm number also falls within the optimum range for greenhouse/nursery growing. This via academic sources.

My current soil pH is 6.8, based on soil test kit and confirmed with slurry/meter test. I’ve been setting my nutrient water pH at 6.3. So, I could range the nutrient feed up and down, or I could just go up to 6.8 for a while and see what happens.

Seamaiden said:

Soil, technically speaking, is a mix of things. As I mentioned previously, all you seem to really be missing from this mix, to make it 'soil' is the mineral component.

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A day can make a difference. You kept me thinking, so I tweaked my searching and also paid a visit to the soilless production facility where I bought the “pro mix”. It gave me an excuse to smell the earth and watch the Cat loaders do their thing – big place. The guy there was pretty thoughtful about it but, like you, came down on the side of soil.

I guess worm castings can be considered a biological component of soil. There are worms in soil, right? Compost is organic matter, full of organisms and even though it may be only 5% of soil makeup, we all know its benefits. So, I’ll stick with it being “soil” and stop beating the dead horse.

Seamaiden said:

So, if you're confident in ruling out any kind of pest, and you're confident that your pH ranges are good, then the next thing to address would be disease. What diseases can cause these symptoms? Nothing I've observed to this point in my growing.

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Not seeing an appreciable difference in flower health/size in affected areas, whether up top or down low. On the plant that exhibits this issue most, growth is not stunted.

Instances remain isolated, this abnormality is not spreading, knock wood.

Overall, I don’t see classic deficiencies or toxicities of mobile nutrients in large leaves at the bottom, of partially mobile nutes in the middle, nor the less mobile nutrients in young, top leaves.

No bugs. Fungus, nematodes, virus, bacteria, abiotic disorders (other than possible pH issue)? Can’t see or think of any. Or, could it be … genetics.

Issue not withstanding, plants look pretty good. If I get them across the finish line with no real decline, I'll be happy enough.

thnx! : )