Hi all. I've been reading recently about RO water having trouble maintaining ph over time when mixed with nutes due to lack of minerals as a buffer. Since I'm about to be auto feeding, I want to avoid this. Would a good ratio of tap to ro water be 20%? So in my 10 gallon mix I have 2 gallons of tap water that's had the chlorine evaporated off? What do you guys think of this? I also wouldn't mind having more available calcium and magnesium for my coco.