@kimkats Working my way through the reading, thanks for sending the links! It says to test your hose water, or the water that is used to fill or mix the plaster. How do I test it? I have never done that so no clue what is in our water.
Have you ordered/received your test kit yet? If so, just pretend like you are testing your pool water but use tap water instead, or if you are filling your pool some other way, see if you can get a sample of that water.