Hey KGB, yes….all feeding is done through the wicks from the reservoir. No top feeding is needed or recommended because of the salt buildup at the root zone. It keeps the bottom 1/3 of the pot damp with nutrient solution. It’s really a slick concept except for the required 1-2 flushes per grow. My memory isn’t that good, but I believe I only needed to flush if using coco. When I used Ocean Forest soil, I dont recall needing anywhere near as many nutrients so I had a lot less salt buildup. There’s plenty of nutes in ocean forest already….at least enough to get through veg.
I’m still intrigued by your earth box….might look at that for next winter grow if they look like two would fit in a 2x4.