Leaf spotting? And Soil PH Issue

So I recently got some stuff to recalibrate my meter but I think I got a defect as it wont calibrate all 3 PHs just the 6.14 one.

Anyways, I took a gamble with it as it read everything with a variable .08-.25 difference scaling up twords more alkaline.

I also got some of those cheap meters you stick in your pots to measure soil ph moisture and light level.

Mainly got them to keep track of soil ph. I just watered them with what I hope is a 6.0 or at least very close water ph.

The meters are reading heavily alkaline (like 7.5ph in soil) but the plants look decently happy?

Also found some oddities on some lower leaf.

Those cheap analog soil meters are garbage .... what medium are you running ?

Give us the full info on your grow ....

Lights
temps
rh
medium
water
ph
nutes

Also that first pic with blotches looks like bug damage. Check leaf carefully top and bottom.

White widow and Bloody Skunk autoflowers
King LED 1500w and a UFO High Bay light both giving off around 600 PAR
Temp around 78-79
RH 60-65%
Originally planted in soil a garden center had made, and transplanted into miracle grow (yes, I know)
water from the faucet, using PH up and down to balance as close as I can get with my junky PH meter.
I gave it a couple shots of bloodmeal, found it was giving nute burn to the tips of the new leaf growth and flushed it.