Leaves are yellow and curly

Looks like potassium efficency to me add some cal mag and potassium they should bounce back in no ti.e if not I'd have to lean towards iron but iron is normally in cal mag so it should help out I use advanced nutrients cal mag extra it's got potassium manganese magnesium. Calcium and iron in it as well as kelp extract I think .... but ya give it a shot if not that won't get better on its own