Leaves with green edges yellow veins

Hello RIU community! long time lurker , 1st time poster. This is my 3rd grow , and after working out the kinks in my room, the 1st grow with good seeds. This one i am having problems with is a Purple Lady(feminised), was a 'free' seed' from attitude.This plant has about 2 weeks left to flower under a 400w hps. My temps,humidity, air flow are fine, and the other plants in the room are doing ok. The problem plant of course happens to be the best looking budsof the few i have finishing. Anyway, the edges are green but the veins are yellow and some crispy in spots. This is not just the fan leaves . hopefully the pics help. Buds look fine, just the leaves.
other info : soil is ff ocean forest, only nutes i used was some tiger bloom. i use tap water and tested pH before and after nutes to see if that was the problem, both seemed normal just under 7. Maybe Mg defcient? i have read epsom salt for that... but not sure how much/gallon?

any thoughts welcome

i wanna say Mag def..but the new shots arent even a light green..but the tips are curling up and your getting the brown spots on teh leaves..i really really want to say mag def..

and its 1tsp per gallon..i use it and water with it/ some people foliage feed with it..they say that it workings quicker..but i dunno..i do wanna ask you a question though..that must be the g13 purple lady? right..if so..did yours double in size when you put it into flowering? how long did you veg for too thanks

Thanks for the response Quickee! I was thinking that too... especially after looking at more photos of the same problem. The question now is.. with just 2 weeks or so left , do i even worry about it?

and yea , that is the g-13 PL, i had her in veg for about 4 weeks. looking too small? i would guess she about doubled in size tho.

id prolly just foliage feed it and then start the flushing of it..but no its looking good..mine did not double in size thats why i was asking..its just kinda bushed out i dunno it was wierd same thing with the free WW g13 stayed the same size and bushed out /shrugs its budding i guess im just gonna end up with less bud

i did want to add sorry..that mag def does lower your yield just for the future ref..so if you see that problem coming you should take care of it quickly..it usually starts with the tips curling or the new shots lime green..

good to know about Mg def. and yeild... like i said only my 3rd go around , so i still have loads to learn. this site is a great community of helpful people tho.
i'll need to keep a closer eye on my girls trying to tell me such things as nutrient deficiencies! also, what could have lead to this Mg problem if that is the case? as all my other plants get the same nutes/water? just in the genes?