how often chlorine?

[AnnaK]

Have you found the Pool Calculator yet?

It won't tell you how often to add but it will help you determine how much to add. The frequency of bleach additions depends on many things: UV exposure on any given day, bather load, organic debris and so on.

Most of us add bleach once a day, in the evening after sunset. You'll lose 1 or 2 ppm during any given 24 hour period and, if you test daily at about the same time of day, you'll soon learn the FC loss specific to your pool's environment and use.

Unless you have an algae problem you really don't need to test twice a day. Pick a time of day that's convenient for you and test then. Many people do this after the sun is off the pool. I test in the mornings because it works out better with my schedule. Add what you need to add to meet the target FC after testing, if necessary.