OK.

With 70 lbs of dichlor into an 18,000 gallon pool, your stabilizer level is now well over 200 ppm.

Please do things on the list below, exactly:

1. Test chlorine levels with an OTO /phenol red drops kit. Tell me the color you see. It may not be anything on the test kit block, but may be a different color.

2. Buy a gallon of distilled (DISTILLED, not anything else) water from Walmart. Test your pH using a mix of 2/3 cup of DISTILLED water and 1/3 cup of pool water. Tell me what result you get, and whether it matches the pH test with straight pool water.

3. If you don't have a K2006, or have one on the way, order one today. With a CYA of possibly 300 ppm, you MUST have a K2006 to manage your pool.

4. Your other option, if you won't want to get a K2006 and follow some rather exotic methods this summer (not particularly hard and not expensive, but weird), you need to hire a vinyl liner builder or service guy to drain 4/5 of your pool and then refill. Trying to drain it your self will either (a) destroy your liner or (b) be slow and difficult

You can NOT do it a little at a time! I just did the math, in an iterative spreadsheet: if you drain 25% of the pool each time, you'll have to repeat the process EIGHT times to get down to 40 ppm of stabilizer!