you big dummy(me) I finally ordered pH pen Dr meter .1 pH pen up n down solution n 7.0 cal solution.don't understand were to start.calibrated pen I think.so I get my gal of water mix in nutes then stick pen in water so how much of stuff do i start off with to change the gal up or down.drops, teaspoon ,etc didn't really get into it.was late.but thinkin this am I thought I'd reach out