Really Need some HELP!!!!

Your plants look good! I see a little magnesium deficiency coming on but that's about it. What dose of CalMag are you giving the plant and how often?

Wood ash would be almost immediately available as a source of Potassium. It does raise PH #'s so be cautious. Bio-Char is always a good amendment for anyone gardening with bacteria/fungi (Inoculants). If lime, it would have to be a very expensive form of soluble lime. I work in Commercial Ag, it's not a cheap option for a small scale problem. What you may want to do in the future is add an amendment that will act as a PH "Buffer". This will "lessen the waves you make in the pool when a change is made", so to speak. . .

FYI: If using wood ash, it should be black hardwood ash. NOT from your charcoal grill (unless you use nothing except hardwood lump)!!

Charcoal brickets have binding agents and petro-chemicals in them that do not break down during combustion. Those ashes go in the trash. White hardwood ash is mostly devoid of nutes because most have oxidized off into the atmosphere.

If you're flushing to remove the build-up, I would flush completely and start from scratch. That way you can go from a clean slate and dial your numbers back in. FFOF does have nutes for apx 20 - 40 days, and for some reason it made your PH/PPM wonky, especially since you said you haven't really added any other nutrients.

Seeing a bit of calcium deficiency and maybe a bit of nitrogen, but otherwise they look pretty good. Start your new nutrient feeding and they should clear up in a couple of days.

In that first picture, the marking on the leaf in the background. Is that from light/wind stress?