A week or so ago I ran into an issue and think I have it resolved. She was yellowing pretty bad, getting some spots and crunchy leaves. I wasn't sure if she was hungry or what.
I did two things to try and help.
I turned the pot off from the res, when the tray went empty I fed three trays of Medina Hasta Grow over 24 hour period. It's an organic fertilizers with myco, humic, fulvic, kelps etc... I mixed itandll strength wich ends up at 1030 ish PPM, about 500 higher PPM than my MegaCrop.
I then mixed a new reservoir of MegaCrop PH'd to 6 and turned the tray back on. I had been keeping it at 6.5.
After a couple days on the res she greened up nicely and no more spots or crunchy leaves.
After much reading I believe my medium should most likely be treated as a "soilless" mix and PH'd as such.
I am using a local mix of coco, compost, basalt sands, biochar, worm casting, expanded shale. Its called myBohemian (Pot)ing Soil from the GroundUp. It is covertly marketed for cannabis.
I have read alot on soil vs soilless mix and what makes a medium one or the other.
It seems that any man made mix based on coco/peat(organic base) and then amended with compost, worm casting, Perlite, vermiculite etc...is considered soilless.
Soil seems to be considered as a clay/sand(inorganic) base with some organic matter mixed in.
So I am planning to start treating my medium like soilless mix and see how it goes.