Plants are losing color and withering at the edges.

I have two skunks that are two weeks in from seed in DWC. After about 7 days the first leaf set began to lose color turning yellow at the edges and now have withered about half way. At about 10 days I decided it probably needed nutes. I put in new water with the floragrow nutes. The ppm is around 300-320ish. The newer leaf sets also began to lose color after another day or so and starting to wither as well. I then proceeded to check the ph last night which is 14 days into the grow. The ph read it was too basic around 8.0 so I fixed the problem and got ph around 6.0. The also leaves look fine where the color hasn't been lost, the veins in the leaves also look normal.

I checked the room temp and I have great air flow. What else could be wrong?