Pool_newbie,

You are asking questions like "how often" and "how much" that don't have an answer, other than "as often as needed" and "as much as it takes". There are ways to answer those questions more precisely, you'd have to have skills and test capabilities you don't have.

The time interval between your questions suggests you may be worrying less about the low chlorine than you should be: you're going to end up with a green pool!

Do ALL these things:

1. Read the muriatic acid page linked in my signature, then go get some muriatic acid -- 1 gallon is OK.
2. Get 6 gallons of PLAIN household bleach.
3. As soon as possible -- tonight? -- begin adding both bleach and acid, but NOT in the same spot in the pool. Make sure your pump is ON, and stays on the whole time.
4. Add the bleach 1 pint -- 2 cups -- at a time. You can add it to the skimmer, if there are no tablets there.
5. Add the acid about 1 cup -- guesstimate, don't measure! -- at a time, added to the water where it flows back INTO the pool.
6. Do NOT handle both bleach and acid at the same time. Do NOT pour bleach and acid into the same spot in the pool, unless there's an hour between doses. DO wear glasses and gloves.
7. Test the water ONE HOUR after both doses. If the chlorine level is not dark yellow, repeat. If the pH level is not below 7.6, repeat.
8. Continue doing this till it's too dark to continue OR until the water is in range.

Once you get the water adjusted once, REPEAT this process every evening, as needed. As the stabilizer dissolves, you should get some chlorine lasting through the day.