No, you don't need to lower the TA before you shock.
High TA will cause the PH to drift up; when it does, you simply lower the PH down to 7.2 with muratic acid. The acid additions will also lower the TA, and eventually the TA will come into range. Now, don't try to adjust PH while shocking- because high FC levels (over 10) will make the PH reading inaccurate.
I'd suggest you lower the PH to 7.2 before you begin, and once you have completed the shock process you can focus on other things.
The cloudy water can be caused by a number of things....in your case it was probably the high CYA was rendering what little chlorine you had ineffective.
High TA will cause the PH to drift up; when it does, you simply lower the PH down to 7.2 with muratic acid. The acid additions will also lower the TA, and eventually the TA will come into range. Now, don't try to adjust PH while shocking- because high FC levels (over 10) will make the PH reading inaccurate.
I'd suggest you lower the PH to 7.2 before you begin, and once you have completed the shock process you can focus on other things.
The cloudy water can be caused by a number of things....in your case it was probably the high CYA was rendering what little chlorine you had ineffective.