We use plain, unscented, generic bleach (mine comes from WalMart), or in states where it's allowed (not mine!) liquid chlorine, which is the same as plain bleach but twice the strength. In a 13K gallon pool, each 3.5 cups of 6% bleach you add will raise your FC by 1 ppm. When you add the bleach, you can add it through the skimmer IF you don't have any of the silk tabs in it. Otherwise, just pour it slowly into the return stream, being careful not to splash it (and wear old clothes anyway!). You can swim within 10-15 minutes after--just make sure the bleach is stirred up well in the water.
If you're having trouble keeping chlorine in the pool, I would go ahead and shock it--for a CYA of 45 ppm, that means raising your FC to 15 ppm and holding it there until you can go from sundown one evening to just before sunup in the morning without losing more than 1 ppm of chlorine. When you reach that point, then you can let your chlorine drift back down, but only into the 3-6 ppm range--with your CYA at 45, you never want to let your chlorine get below 3 ppm. (see the "best guess chlorine chart" linked in my sig for more explanation on this).
Do you know what is causing the chlorine demand? What do you normally use to chlorinate? What was your CYA level at closing last year? What other chemicals (ingredients, not just "shock" or product names) have you added before now?
Welcome to the forum!!
Bookmarks