Rust Fungus on leaves

Am at day # 13 of flowering White Widow and have spreading Rust Fungus on leaves. Just sprayed with
a solution of Baking Soda and water to try and stop this.Any other suggestions ? The PH is right on and their
is no Cal-Mag deficiency.

There prob gonna need some photos sarge.

check this

Nutrient Problems with Pictures - Cannaversity http://www.cannaversity.com/cannaversity/article.php?id=057

I seem to be having the "Rust Fungus" issue too. I'm finding out that my whole house water filter and reverse osmosis filter is stripping good stuff as well as bad stuff from the water. I'm going to increase the CA/MG Plus in order to replace the calcium and magnesium that's being stripped during the reverse osmosis filtering. I use Ocean Forest soil. Ph'd water at 6.3 to 6.5 (6.5 is the lower end for calcium and magnesium uptake). I'm using high quality nutrients following a pattern of FEED, WATER, WATER, FEED. On the WATER days I add 1 TBS of Molasses per gallon. It usually works out that it's an every other day feeding/watering. So in essence it goes Feed, nothing, Water, nothing, Water, nothing, Feed, nothing....etc... I use 5 gallon buckets and 1 1/2 gallon of nutrient water or water with molasses gives me good run off that I know the soil was saturated. The Rust spots aren't there in the Vegetative stage. They only become apparent in the flowering stage. I'm almost certain it's due to a lack of calcium and magnesium. I'm going to add the CA/MG Plus to the "Water (and molasses) days too.