Right now, it just looks overwatered. If it does in fact appear to be burned, than you'll either be dealing with nute burn or a magnesium deficiency. Magnesium Deficiency looks very similar to nute burn.
If your plants burn, flush for 3 or 4 days. If that doesn't help, foliar feed a teaspoon of epsom salt to a gallon of water.(Foliar feed= Spraying the surface of the leaves-Top and bottom)