A few months ago, I asked for advice on testing for water quality. I then bought two "different" kits for home water testing.
As you can see in the photo, the kits are nearly identical, but I couldn't tell when I ordered them.
The kit on the left has two sets of tests for coliform bacteria, nitrite and nitrate, hydrogen sulfide, hardness, alkalinity, free/total chlorine and chloride, copper, sulfate, iron and pH. The one on the right has two additional tests (lead and pesticide). I bought the right kit from Industrial Test Systems for $53 (incl shipping). ITS also made the kit on the left, which I bought for $33 from Forestry suppliers. (I have no idea if the 2 extra tests are worth $20...)
So I tested my Berkeley tap water and everything SEEMED ok.
My opinion is that nobody buys these affordable kits because they are hard to use -- different immersion and waiting times total to one hour of dip, shake and then compare to the reference card. They are also VERY imprecise. I have no idea of whether I did the tests correctly or if I was missing a bad result.
Does anyone have other experiences to add?
So my intuition that the water test market needs innovation was true. We need a reusable, fast, digital, test-kit-on-a-chip. Even a $2,000 version would sell (to someone who would deliver a "service"), but we ultimately want a $5 version in every house.
So get going, inventors!
Bottom Line: We don't use things that we don't understand or trust. Simplify!