Yes, we're talking about household bleach, but it needs to be plain, unscented....no added perfumes or "extra whitening ingredients" or anything fancy like that. In a pool your size, 3 cups of 6% bleach will raise your chlorine by 1 ppm. How high you need to go depends on your CYA level, which you need to test for. A pool store can test for it, but make sure they're not using strips--make sure they're using the liquid reagents. It isn't silly to go to the pool store for testing, as long as you don't buy any of the chemicals they try to sell you, right off the bat. For example, pool stores worldwide will convince people that their calcium is WAY too low and they must add some RIGHT NOW!!! but calcium is irrelevant in a vinyl pool. Or they'll try to insist you need to buy 4-5 pounds of alkalinity up, which is the exact same thing as Arm & Hammer baking soda at 5 x the price. So....I strongly encourage you to invest in a good, drop-based test kit and forget the pool store. Taylor carries a good one, but most of us use the one sold by the owner of this site. Cost is $70, but it will test for most anything you need, and pay for itself over and over again in the first year. It'll also keep you from getting "pool-stored"!!

Since you referred to the tabs, I'm guessing you've been chlorinating with trichlor, which confirms my suspicion that your CYA is way too high--but have it tested anyway and post back. And when you add bleach to the pool, you can either walk around the perimeter and stir as you pour, or pour it directly into the return stream, it doesn't matter--just make sure it doesn't collect as a "hot spot" around th edges of your liner. It is better to shock at night, so the sun gets as little of your chlorine as possible, and I would stop using the pucks for now until we have a good CYA number.

Janet