River water is very dependent upon what and how long the water has been flowing through. Rainwater is going to be around 0 KH. It is basically distilled water. So river water is usually very low KH as well. As it flows it does pick up minerals, but with full streams and rivers that can be quite low. In drier times with water flowing over limestone, for example, it will pick up a lot of calcium and increase in hardness. But surface water is mostly very low in hardness. Ground water is usually the opposite as it is water that has percolated through soil and rock. So well water will normally be quite high in KH. My water in my previous house was from a community well. It's total alkalinity was over 200. My current home is now on a city water system where the bulk of it comes from reservoirs. It has a total alkalinity of 50-60. Although I think a bit higher would be ideal for what I like, I don't worry about it or try to increase it. I have however recently found information that I will not use that water to rinse eggs in or to moisten the incubation media. For the turtles, though, I don't worry about it.
THANKS BUNCHES, Mark!!!!!!
I always learn so much from you!