Help my Girls- PICS

Hi Everyone,
I thought my girls had a mag def so i repotted them into bigger pots with all new soil (They needed to be repotted anyway) but before i repotted i flushed em. This was last weekend and it seems that the problem is still on going. I watered with Epson salt(1 tsp -gallon) a couple a days ago with no changes. I'm now questioning is this a Mag def or possibly something else like my water. I always ph my water to 6.5-6.6. Ph run off is 6.6-6.7 on all girls, so i can't see it being a ph problem. I'm going to buy a water filter today called ZeroWater which is suppost to lower TDS to 0. My soil is FFOF and i just repotted with new soil and haven't nuted yet-but some plants seem to have gotten darker in color from new soil, but still having yellowing coming up. it seems to start at tips as over nute but then porgresses to interveins and necrosis. Can anyone confirm what these pics look like?

When you spot a dead leaf the best thing to do is take it off asap! If it's a disease(bacteria) causing them to die, it will help slow the progression. And you cant bring back to life the dead anyway. And water does not need to be at absolute zero between 1 and 10 ppm's is fine. And try to keep the ph of the soil between 5.8 and 6.4. But some sativas may like a ph slightly higher than that depending on the strain.

thanx for the info Canad but someone told me they think its a Mag def Trying to confirm this.

this does resemble mg def, but since the photos aren't real clear, it's hard to tell exactly. If you've given some epsom and there's no change, it might be another nute that is missing. In a situation like this I usually tell people to go get some Dynagro 7-9-5 fert at your local hydro shop. This fert can be used for either hydro or soil. Just follow the dosages on the back cover. 1/4 to 1/2 teaspoon for soil in a gallon of water. What's good about this fert is that is has pretty much all the nutes plants need, including calcium and mg. Don't over-fertilize however. Let the soil dry out quite a bit, then water with some fert in a gallon of water until water runs out the bottom of the pot. Then let it dry out some again to put oxygen in the root zone. Try this and see what happens.