PH fluctuation with outdoor grow.

[Santa.ClausHOHOHO]

I will try to be brief, getting ready to water.
Outdoor grow in the ground. Soil was amended with compost in the spring. Pretty good soil. But, I do not know the ph of the soil.
My well waters ph is at 6.9 to 7.0 I normally do not add any ph down, figure I am in a decent range for outdoor and in the soil of the ground. Just for giggles I check the ppm of the water, right at 250. Anyways, I seem to be running into some deficiencies. I have been dealing with Leaf Septoria and have it in check, for the most part. That shits a bugger. The several of the leaves are looking different and I seem to be a bit slower in growth. I am 6 or 7 weeks into flower, nice Buds forming but they seem to be slowing a bit.
I guess I should get to my question. Thinking it is a calcium & Magnesium deficiency. I have read in articles that cal & mag are best absorbed with a ph range around 6.2 to 6.5 Question is, is that considered to big of a fluctuation in ph, been watering at around 7.0, now I am going to water at 6.4 ish with a cal mag supplement ? Attached is a photo of the new symptom I am seeing... It looks a lot different that the Septoria

 

[Tracyfri]

If you've got compost in your soil you're okay watering with that pH. Really you don't even need to consider it. It kind of looks like septoria symptoms you know sometimes it doesn't all look the same it's not always just spots. We had it real bad last year where I am and there was plenty of it that looked just like that leaf you have pictured there. I'd imagine things to be getting back to normal if you got to handle on that stuff what did you use for it? And you've noticed a slowdown and the spread of it or septoria that is?

 

[Santa.ClausHOHOHO]

Seemed to notice a slow down in growth of the buds. I guess Septora will slow down growth as well, I have been using Lost Coast for the LS. I am noticing the symptom on just the larger fan leaves, so far.
I have a batch of cal mag mixed up, hate to waste it, I am thinking of lowering the PH down to maybe just 6.7 or 6.8 The PH did bump up when added cal mag, up to 7.4

Then I will do a morning spray of LC. darn sun is getting higher in the morning sky though.