Soil (potting mix) with a rough 25-30% perlite mix. Using goliath product veg and bloom parts 1 & 2, at a half dose. Also with an added bio feed tonic which "also contains trace elements" 1 teaspoon epsom salts, ph'd from tap water reading 8. Bringing that down to 6.8 before feeding. slurry ph check tells me soil is holding at 6.8.
16l tubs! Diy flexi tubs drilled out. 4 weeks of veg 16l hopefully enough space without becoming root bound.