I seem to be getting tip burn but not nute burn just literally drying up and getting crunchy and turning a dark color.
ah yes, GD rockwool. Do yourself a favor and throw it all out. Either buy or build a cloner. I am going to test out how well a fogger unit works, maybe in the next week or so. Try using a 1:1:1 if using 3-part, or just invest on 1L of clonex for the solution (and gel). Also you can try (with the above) some rapid rooters/root riot plugs.