Alright, I've got the seedlings (growing their second pair of leaves) in the bubbler and I added Advanced Nutrients at 1ml/l, but the water PH still rises to about 8. Hardly it's the rockwool this time?
These very much ARE PH perfect. That's why I think I've got an issue. And I've also tried with vinegar, but it still rises from like 5.7 to 8 overnight.
