I think it's a Mag deficiency. but I'm unsure. Please help, pics.

I'm using DWC bubble buckets and have been feeding them the lucas fomula with GH line of nutes. I'm thinking that I should have done some sort of flush when going from veg to flower.

Are you using tap water?

I think you're on the right track with mag, the question is, is it from a straight def or is it an OD of another nute or a ph issue that's locking out mag.

Yep, classic case. Get 'em some Cal/Mag Asap! Like dude says, make sure you dont have too much Ca or P locking it out.

tap water, ppm of 70.

i get this prob some times with my tap, i recommend adding half a vitamin pill to the water it will save you some cash. been doing this for a while for calmag works very well

I'll be adding call mag tomorrow... do I just add it to their already mixed lucas GH formula?