How much Chlorine is too much?

[aylad]

In a pool your size, know that 1/2 gallon of 6% bleach will raise your Cl by 1 ppm, so if you know your starting point, you can calculate what it will be based on what you add.

In the meantime, to get a ballpark estimate of your current chlorine, you can use CarlD's patented "shotglass method", which consists of mixing one part pool water with 1 part of distilled (non-chlorinated) water. Mix well, run your test, then just multiply your result x 2. If that's still not high enough, you can mix it 1:2 and multiply result x 3, etc. Each time you dilute it you're losing a little accuracy, but it'll give you a good ballpark estimate, and there's enough leeway that even if you overshoot by a little due to the dilutions, you still won't damage your liner.

Janet