it's fox farm.... you are following instructions... it's probably locking something out or really acidic. They tell you to feed WAY too high of EC.
check ph of runoff... realize it's only a hint of what the soil actually is, but if something is batshit crazy it'll stand out. Do tht first as it is easiest and less intrusive.
a soil slurry is an option too.. don't use top of soil as it has a lot more evaporation going on and shouldn't have many roots that superficial anyway. whatever pH water you use.. what results merely points in direction of actualy pH ... it shuld stop a bit short of your target soil pH... if it goes further, the actual pH is likely even lower -- you are seeing weighted average of the water you used with what dissolves from soil into it. highly unlikely it is alkaline using FF nutes.
After looking at recent week, i am twice as confident as before tht this is lockout. you are providing cal mag.. so, that isn't the cause. either pH locking out various thing or too much P/K can have similar impact...
i'd drop back P/K components of mix after ensuring pH isn't major problem. ~6ph is fine.. you are mostly soilless with a minor supersoil/FFOF component.
the irrigtion methods for soilles and supersoil/soil kinda contradict each other. you want 10-15% runoff with soilless to maintin pH and nute concentrations in soil... 10-15% runoff just leeches the good stuff from your soil/supersoil at a faster rate than necessary. i'd think about doing one or the other. also, super easy to diagnose a soillless or hydro grow.. you can calculate ppm from guaranteed analyis labels and no guessing on what concentrations the soil/supersoil contains and of what.... supersoil and soil is a bit more of a balancing act... consistency of putting it together, then adjusting based on what you see each grow to avoid problems the next run.
both are great options, don't ge tme wrong... i clearly have a bias for soilless/hydro... total control, easy to adjust.
soil/supersoil can be even easier maintenance... simply add water.. how fucking cool is that? bit longer road to get there... potentially better tasting buds according to some.
