White widow/northern lights Wilma grow

I’ve started giving them their first feed for there second week I’m starting them off at 1/4 strength nuts after there first week of r/o water I’ve also started to use cal mag plus in a foliage spray to help keep things humid I’m a little worried about one white widow plant I’ve stared the picture she seems very slow and hasn’t grown much only time will tell and I’ve hooked up the Wilma it’s set to two 15 minute feeds a day using the flood droppers first time using the Wilma so It’s a little trial an error to get it right the ec is 0.4 and the ph is 5.9 I’m planning on emptying the tank out weekly and replacing with fresh nuts I’ll be flowing the advanced nutrients app feeding chart I’ve got the whole line of nutrients so hopefully all go’s well.