I'd say over water but it's a dwc right? Lol, copper causes wilt... Since your hydro you need your ph to be strictly 5.5-5.8 or you will lock out most nutrients the plant needs .. Magnesium needs a pH of 5.8-6.0, zinc needs 5.4-5.5,sulfer needs 6.0 exactly and molybdenum 5.6-5.8...And there's...