advanced nutes can be a pain in the ass,and the yellowing in flower is due to a lack of nitrogen and following their charts too closely lol.if you want to try something easy and very ph stable try this
http://hydrodynamicsintl.com/ionic-grow-for-soil.html
i use it in promix,coco,and hydro and it works very well.been using ro water for a good 6 years,might use calmag once a month on a picky strain like nute hog og's. if your feeds are strong enough calmag is not needed.i have a gallon of calmag that has to be 2= years old by now and i run through about 30 gallons of water per day lol. but the ionic is easy 3 parts,grow for veg,bloom and boost for flower.i like to run all my plants on grow nutes for first 15 to 20 days of flower untill they are done stretching,then switch to bloom nutes.the plants dont fall on their face and turn yellow doing this.that works with any nute and i also use alot of jacks classics and do the same thing. but i ran a/n nutes for a good 2 years,never could get my plants to look as good as they did with any other product.even pure blend pro worked better lol.ionic also makes a hard water formula that will help with dirty water,they just use much less micros in those mixes.let me know if you have any more questions,peace