soil ph can drift rapidly and seemingly randomly
i don't have a soil probe, but i routinely test my run off. i understand run off is notorious for being inaccurate, but i use it as a guide only - if i run 6.5 in to the pot then the run off gives me a good indication if the ph is drifting upward or downwards, and i'll adjust my next feed accordingly.
if your in-pot PH has risen even a little bit in to the 6.4 or lower range, it will interfere with her ability to uptake Calcium (6.5 and higher in soil for Ca) - i'm having a similar problem, so have raised the calmag dose just a little, and raised the ph of my nutes to a little higher to compensate.
i use a lightmix soil and it frustrates me.
don't water too much.
don't under water.
avoid air pockets but the water will run through the path of least resistance and requires multiple small watering sessions for full saturation - it takes me way too long to run a couple of litres through a pot.
allow wet/dry cycles but drying soil causes ph inconsistencies.
time it takes to see changes in your plant after adapting feeds to suit them.
i'm sure there a more things but these are daily annoyances for me.
other people love the stuff.
finishing up my 3rd round of soil grown plants and then switching to coco to see if i enjoy working with that medium better.
a probe is infinitely better than my method, just sharing what i do in the hope that it helps you out.
