I wrote that page about 15 years ago, and need to re-edit it again.

The better shocking method requires that you have a sand filter and use calcium hypochlorite, which is MUCH harder to find than it was 15 years ago.

Also, it won't do anything to solve your current problems. You need to start adding a box of 20 Mule Team borax (slowly, via the skimmer, pump running) every 4 hours for every 10,000 gallons in your pool, till you get your pH above 7.0.

And, you probably do NOT want to bring your chlorine level down. If it's been at all sunny, and your chlorine level hasn't dropped on it's own, it's probably because your stabilizer is very high . . . and in THAT case, you NEED high chlorine. Read the "Best Guess" page linked in my signature, for the explanation.

And get a kit. You can NOT do a good job with your pool, without good info, and 'guess strips', even when read by a dealer, do NOT count!