Do not use those numbers from the runoff. A good majority of commercial potting mixes are pre-buffered to keep near the 7.0 range. With an aquarium test kit, it's a color coded result, and results are skwewd by the tint of the run-off water. 7.3 tapwater should be fine after adding yuor additives and nutes. A few drops of vinegar or lemon juice on non-fertilizing days to bump the tapwater ph lower should help.

I'm not impressed with the Cha-Ching, but if you're careful it does no damage.
Have not really seen where it does any better than molasses, actually. I use 1 tsp unsulphered molasses:gallon of water, virtually every watering. (but none on feeding day)
Rusty Trichome Reviewed by Rusty Trichome on . YELLOWING...DRYING UP FAN LEAVES.... What is your experience level? NEW-B Your Equipment: .1) Type and wattage of lights. 400W HPS .2) Distance from tops? 12-18 INCHES .3) Reflector type? BRIGHT STAR, NO GLASS, NO COOLING .4) Is there a consistent fresh air supply? I BELIEVE SO .5) Do you have an exhaust fan and a circulation fan? YES .6) What are the bulb wattages, kelvin ratings, and schedule? 12/12 Your medium: Rating: 5