How do you know how much nutrients are left in the soil? I feel like I get plants, they grow to a certain size and then start dying, and I would imagine the soil nutrients are partly to blame. Do you keep a compost pile and add to the soil occasionally or add fertilizer at predetermined intervals? Apologies if these are maybe dumb questions, but you seem to have a lot of experience with this kind of thing.
Since I am using Foxfarm ocean forest soil it already has nutrients in it for many months.. But eventually we will start feeding them using fish fertilizer and other liquid fertilizers.
I have never used any liquid fertilizers before, so perhaps that has been part of the problem!