Unknown rust on 7th flowering week

Hey mate try hydrogen peroxide 3ml 20% concentrated into 1 gallon of pure water for 2 to 4 days. Also seems more of those micronutrient deficiencies or possible root rot causing the leaves to die prematurely. After hydrogen peroxide flush ; try giving only some of micronutrients like iron, zinc ,molybdenum,sulphur..hope that helps.

I would not say cal mag. Need to check your runoff water to see if your plants have nute lockout. I see all the nutes you use. You think you need to use all those pricey nutes those companys promote. So many people fall for their products thinking their plants have to have this whole line. Problem is when using all this different stuff it just helps for lockout to happen. Then flushing. If you don't use all that crap and you water feed water feed etc, having to flush becomes a thing of the past. I live by the moddo keep it simple stupid. I use GH floranova for veg. It is a one part formula, all you need for veg. This stuff is so potent 1 gallon will last 5 times as long as other nutes and is very effective. Don't need the other crap that supposedly makes your plants stronger, an oscillating fan does that. When I switch to flowering I use cannaflores which is week mixture for the price. I add Massive bud formulation to boost the the week canna nutes. That is all my plants get and my plants are usually healthy to the end. Hope this helped