Just like the how-to says:
Originally Posted by RafaelS
Test and adjust chlorine levels as frequently as practical, but not more than once per hour, and not less than twice a day. Chlorine additions should be frequent, especially at the beginning. Algae and other organic debris will consume chlorine very rapidly at first. As things progress, you will lose less chlorine each cycle and can add chlorine less frequently.I'd check it after an hour and see how much was lost. It all depends on your schedule and how much you're losing each time. It's hardly worth the effort to check hourly if you only need to add a cup of bleach to replenish it. But if you lost almost all of it, you need to keep on it.