My salt water pool water has algae in it and I want to superchlorinatebut I don't understand how it works. I do have a superchlorinate switch on my machine. But how do you know how long you need to do it/how high the level needs to be? Does it need to get to the breaking point? How do you determine that? If I superchlorinate for 24 hours, it seems like the chlorine level will be way high and it won't get within the proper range for several days to a week. Maybe I don't have to do it for that long??

Hi, welcome to TFP! Do not use the superchlorinate function on your saltwater chlorine generator (swg). It is not an efficient means to kill algae and will shorten the life of your cell. We recommend using liquid chlorine for the shock process instead. Also you need a high quality FAS-DPD test kit, such as the Taylor K2006 or the TF 100 which are capable of testing free chlorine (FC) levels greater than 5ppm. Most pools require FC levels greater than 5ppm to reach shock level. You will need to dose the pool frequently to maintain shock level until the FC drops 1ppm or less overnight. Read defeating algae and
how to shock your pool for more information on the shock process.
If you post a complete set of test results we can help you get started. You can have the water tested at your local pool store until you are able to get one of the recommended test kits.

I would also recommend liquid chlorine, you want to get the TC value up quick and maintain it the quickest way is using liquid chlorine. Have you used www.poolcaculator.com? You put in you known values and it provides recommendations for amount of chemicals to use. It would help to know your CYA level that also drives your TC level you need to reach to effectively shock.

Remember shock is a process not a product. pool-school/shocking_your_pool