For checking water ph, I use my (freshwater) aquarium test kit. $6.00 or so at any pet store. My well water is very consistent, so I only check it once in a while. And since I know how much ammendment it takes to adjust the water to 6.8 or so, I use the whole kit in maybe 18 months to 2 years.
Just another option.

Also...I've done the coffe grounds thing, but was using my regular ferts, too. Ended up burning the ladies a bit. To me it's better to adjust my ferts a little at a time till I get repeatable results, grow after grow. Weird additives may work as claimed...but...It seems to make my job tougher in the long run.