What are those holes? Are those from pests?
No, it's expanded clay marks. Turns out that if you naively pack the expanded clay balls in a planting cup for #aquaponics #hydroponics or #aeroponics, the plant can suffocate and die. This is how it looks like when it happens. That's why my book recommended adding some coco fibers or other soft filler material to the cups. I ignored it.








