1. Stop taking water samples to the store -- the goal of pool store testing is to sell chemicals, not solve problems.

2. Go to Walmart and get a cheapo OTO/phenol red drops kit PLUS 6 gallons of PLAIN 8% bleach.

3. Go to Lowes, Home Depot, etc and get a gallon of PLAIN 31% muriatic acid + some blue / purple nitrile gloves. If you don't have sunglasses, get some safety glasses, too.

4. Add 4 cups of bleach this evening, after making sure the pump is on. Wait 30 minutes, then add approximately (eyeball it) 1 - 2 cups of muriatic acid. But first read http://pool9.net/ma/ and WATCH the video!

5. In the morning, your chlorine should be up, your pH will probably be down. However, after the first session with kids in the pool, your pH will rise back up.

6. Tomorrow, read the SS Recipe (even though you can NOT follow it at this point) for info on operating Intex pools. And, read the alkalinity page.
http://pool9.net/ssr/ -- http://pool9.net/alk-step/

7. Once you've read those, you should understand why you need new cartridges, and also that you've begun lowering your alkalinity.

8. BUT . . . you need to ask yourself, Why? Without a heater, and without a salt water system, the ONLY reason you need to lower your TA is either (a) because your pH is unstable and constantly going up OR (b) because you also have high calcium and the combination of high TA + high CH is causing your cloudiness.

Good luck!