How often do you find you need to shock?

[chem geek]

In an outdoor pool exposed to sunlight and where you keep a generous (Ben's Best Guess CYA chart) level of Total Free Chlorine (FC), then you normally do not see your CC rise except immediately after some moderate-to-heavy usage. The CC will typically revert back towards 0 unless your chlorine demand (usage) is heavy over an extended period of time. However, if you get too much CC and your FC was too low at some point, then you can get CC that is "stuck" and will only breakdown from some serious shocking and sun exposure.

People using a Salt Water chlorine Generator (SWG) typically find CC at 0 almost all the time and rarely if ever need to shock their pool. People using manual dosing of liquid chlorine or bleach sometimes have to shock, but how frequently depends on usage, exposure to sunlight, and how well FC levels are maintained. There is speculation that dosing less chlorine more frequently might be better for keeping CC at 0 as this is more similar to what the SWG does.

People also shock their pool when they get algae in which case they keep their pool at a high chlorine shock level until the chlorine is no longer consumed by the algae (determined overnight when the sun doesn't shine) for a day or two.

I'd be interested in hearing what others have to say about this. From my scanning the forum it looks like what I said above is typical, but I'd like to hear from others.

Richard

[mbar]

I only had to shock my pool once this year - that was after it was flooded with all the rain in June. I test my water every day - I add bleach as needed to keep it in the mid level of the chart according to my cya.

[aquarium]

We started with all new water June 1 this year, and started BBB a week later. It's been clear blue so far but I noticed that it won't hold 1.5 ppm chlorine (OTO) overnight anymore, so I just put a big jug (174 ounces) of the 6% bleach in - 15,000 IG pool, CYA ~30ppm. Never really had a water quality problem, but the water now is -really- clear.

[medvampire]

I have had to shock twice. Had a bunch of kids and a storm witch dumped a bunch of organics. My CC hit around 2 so I dosed to a level of 25 and held it there for a day or so. My CC droped to around 0.5 to 1 and held there. I dont have a feally good test kit this year. I have a DPD but not a FAS-DPD. I bought this kit before I found this site early in the season. I WILL have one for Ben's kits for next season.
Steve

[ChristopherS64]

My CYA is around 40 and I keep my CL between 2-5 ppm and have not shocked this year