Quote Originally Posted by Watermom View Post
If your fill water has a CH of 90, how did your pool's CH get so high?
That's a question I have as well. In the past, I've always relied upon the pool store to test our water. It's always been in the middle of the expected range when they tested it. Yesterday we ran a sample over to the store for a comparison, and they returned with 210 as the CH level. For all I know, it's been slowly climbing or high for years.

I re-ran the test this morning, on both the pool water and the water from the hose. My test consisted of applying drops of the reagent, swirling to mix, and looking down the comparator tube to the white (red/pink at this point) dot at the bottom of the tube. I applied drops of reagent until that dot turned blue. Maybe my testing process is flawed? I had been looking at the color through the side of the tube, and ensuring the entire thing was blue...which accounted for the higher reading. Which process is correct?

My results:
Pool water: 300
Hose water: 90

I do not fully understand what raises CH levels. I've read that applying chemicals that contain calcium can do it (makes sense). I've used many of Leslie's products over the past 4 years, for whatever they recommended. While that may not be the cause of the CH level, it may have contributed. Sadly, I don't have the ingredients handy.

Also, every year I have to fill in some water from the hose. Even with the application of an Aqua Door and plugging up the holes in the skimmer and return port I still lose water to below the skimmer. I'm hoping that as long as my CH doesn't rise, I can slowly bring it back down into a more acceptable range with those refills.

Thanks for all your help!