If chlorine is kept at proper level, is shocking ever necessary?

[Watermom]

Around here, we don't think a cya level of 80 is fine, but you can compensate for it by just keeping your chlorine level high. (We actually recommend cya of 30-50.) But, at any rate, with a cya level of 80, you need to keep your chlorine level between 5-10 all the time, and whenever you need to shock it, you need to take it up to 20. While you are trying to clear the pool, test the water at least 2-3 times a day as Janet suggested above, and each time, add enough bleach to take the chlorine level back up to 20ppm. The key to killing algae is to sustain a high cl reading. If you let it yo-yo up and down, you will never get the water clear. In a 25,000 gallon pool, each 3 quart jug of 6% bleach will add just under 2 ppm of chlorine to your water. Also, run the pump 24/7 while you are working to clear it.

At this time, don't add anything else. The pool stores will tell you that you need a bunch of different products, but you don't. Just bleach. Take a look at the 2 stickied threads at the top of the algae forum. Those pics should convince you that bleach is all you need.

Keep us posted about how it is going. Any more questions -- ask away. Somebody around here will try and answer. Good luck.