leaves whilting and turning red and yellow storks

please help my 3 iced grapefruit are 4 weeks into flower and the fan leaves are turning yellow and red and drying up wat shuold i do about really worried as dnt wanna lose me bud a;l the other leaves look fiune just the fan leaves and the fan leave stalks are red plz hel

Your second photo looks like it shows nute burn. Your lights make it hard to really see what is going on.

aye fert burn.

dont go strictly by ppm, u got to have your ratios good as well

red may mean potassium(K) or Zinc(zn) problems pic haed 2 see

wat should i do next just give them water or wat i dont know dnt want them to die plz help

Straight water for a while.
The damage should stop spreading then, but the burnt leaves won't repaire themselves.
Trim off the damaged part of the leaves.