Calcium Deficiency:
Young leaves are affected first and become small and distorted or chlorotic with irregular margins, spotting or necrotic areas. Bud development is inhibited, blossom end rot and internal decay may also occur and root may be under developed or die back. Deficiency will cause leaf tip die-back, leaf tip curl and marginal necrosis and chlorosis primarily in younger leaves. Symptoms: young leaves develop chlorosis and distortion such as crinkling, dwarfing, developing a strap-like shape, shoots stop growing and thicken.
Calcium Toxicity:
Difficult to distinguish visually.
May precipitate with sulfur in solution and cause clouding or residue in tank.
Excess calcium may produce deficiencies in magnesium and potassium.
in my experience, if it is a overdose than mag will usually get locked out of some of the more sensitive plants.
if u determine that is a deficiency, than you better lower your base nutes if you want to add more calcium or else your ppm will skyrocket into death zone.
cutting edge solutions makes high quality cal. and mag. in individual bottles which is kinda nice since not every situation calls for both, and they dont have the nitrogen in them like cal/mag products do, which is nice for us people who like to cut the nitrogen out of the feedings for the end of the flowering cycle.... they are called plant amped and and mag amped if anyone is interested.
thats all i got lol.