Heya Sox21!
Looks like its looking for some more potassium! Potassium deficiencies start with yellowing and burned edges/leaves. It can sometimes turn them white almost which I almost see in the one picture on the leaf edges.
You also want to make sure pH is in the correct range. In soil, potassium is best absorbed by the roots in the 6.0 – 7.0 pH range. In hydro or coco coir, potassium is best absorbed by the roots in the 5.5 – 6.5 pH range.
Add in some more nutrients, specifically with some potassium and keep an eye on the recovery.
Cheers and good luck!