You can save them if you act fast. Get a good PH pen. I bought a cheap one, and it went bad. I PH acording to the pen, and was actually in the 3.0 range. It burned them, and only save 2 out of 8 plants.
I would check the PH, if its low, run them under the sink until it comes back to 6.4-6.5. Thats the sweat spot for soil. Let them completely dry out for a few days, then slowly back on the nutes. Start out at half strenght. Thats the best advice I could give ya.......Keep me posted......