So glad I checked out your pics-
I’ve been thinking about putting a plant in an unused prefab shower we have.
Must be nice to have a water source and drain right there.
Could even take off shower head, add an automated drip and maybe mini fert tank to it and just let it run through a netpotted plant into your pipes. I’ve got a septic sys so would probably use organic feeds for mine.
Your actual question?- I’d say maybe try dropping your pH and giving some good fungal feeds to boost your plants immunity and terpene production which the plants use to ward off many pests and non-beneficial fungi (molds).