Lower leaf yellowing + spots (pakistan ryder, bubblecious)

hello,
so i have problem here with pakistan ryder and bubblecious, both autoflowers.
My water is PH'd everytime before nutes and after, it's in 6.3 - 6.8 range, run-off is 6.4 - 6.7.
Last week started feeding with biobizz grow 4ml/litre, and i thought this is some cal/mag deficiency, sprayed them with biobizz alg-a-mic and added alg-a-mic to watering 2ml/litre. It's in some potting soil, i know it's good because other people don't seem to have problems with it.
One grow before i had some problems in earlier stages of veg, they were yellowing all 'round.
New growth looks super healthy.
Maybe you guys know what this is?

really, no one?

It's maybe the dirt or your nutes were too weak,
but then you started feeding last week so it improved.
I measure feedings by a ppm meter it's more
accurate and you know exactly how strong
the nutes are, going by the label is good to get
it in the ballpark but it's not as exact~