Need info on BBB

[pcasey61]

Janet;
Thanks for your quick reply, you provided a wealth of information. As for my water readings, yesterday I got no reading at all for chlorine or PH. At the pool store they told me my PH was well below 7, Alkalinity was 0, and calcium hardness was 60. I added 12 pounds bakung soda and 10 pounds Hard-plus last night, then 2 three inch pucks in the skimmer today. I checked the Chlorine this afternoon and it was ideal. The PH looked good too, slightly low but I am sure another couple pounds of baking soda won't cure.
I thought I knew it all, but after searching this site I am embarrassed by how little I know. I read a lot about CYA, dont really understand it all but I know I don't want it in my pool. Lastly, I routinely shock my pool once a week or so just to give it an extra zap of chlorine because the pool sits in the sun all day and we have a pretty active swim load. From what I read on this site it sounds that true shocking actually entails some sort of chemical reaction with the water. I don't really understand all this, I guess I have just been lucky for 10 years that the pool has pretty much run itself.
Thanks very much Janet, I appreciate the help.

[prh129]

CYA is a stabilizer that helps the chlorine from being consumed by the sun. The higher the CYA level gets, the higher the chlorine level is needed to do its job. Most people here shoot for a CYA level of 30-50 ppm. If you look at the top of this thread, you will find Ben's best guess chart that shows you what chlorine levels you need for a given CYA level. Tri chlor pucks contain CYA so using them will cause your CYA level to increase and also make your pH decrease so you need to keep an eye on those things. A lot of people here use bleach because it adds chlorine without anything else.

By testing for combined chlorine (CC) or "used up" chlorine, you can tell when you need to shock your pool. CC can cause eye irritation and give off a strong chlorine smell. Raising the Cl to shock level gets rid of the CC.

By shocking once a week you might have been using more chemicals (costing more $$$) than was necessary.

Peter