red stems and leaves curling down first week of flower

Need some help I'm in the second week of flowering I have red stems and leaves are curling down I though it might be a nitrogen deff so I added so grow big which has plenty but it didn't help and now my leaves are curling down I think it might be a lock out now I gonna flush my Ph is around 6.5 any suggestions

Some pictures would help

N def never causes red stems

We'll the I thought I red that but maybe.something todo with phosphorus maybe some sort of lock out and some of the new leaves the tips are twisted a bit ill try and get a pic its tough to see with the lights