Thanks for all the great responses. Ever since deciding to build the pool I've hoped for a digital chemical reader, where I dip it in the water, and it instantly gives me a digital readout of all chem levels, and/or tells me exactly how much of what to add to bring the water into balance. I wonder what such a device would cost or if it's possible to build!

I grew up with my pool owner friends' parents always doing the "strips" or the dropper test, and always felt it very subjective. What if you're color blind, or what if your strips are bad, etc...