Yellow spots, (Leaf Septoria)?

leaf septoria is a bunch of pail spots.. think this is nutrient related. canoeing and rust on tips.. could be a few things.. first, ensure what you give it is properly pH's second, use my or any other nute calculator and add up what you provide to help deduce what's going on or if something is missing. pH, concnetrations and ratios of what you provide are all equally important to availability of each individual element to the plant (internal chemistry, not selective due to roots.. water is absorbed through a semi-permeable memebrane.. no 'selection' is happening there unless the molecule is literally too big to fit through.) the heat could be causing the canoeing too, but the tip burn isn't. you can use a leaf chart (also linked in my profile comments - same with nute calc), but you'll want to calculate ppm of what you feed if you expect to make an educated guess as to what is going on.