Yup. I stopped selling it because it only works when folks read and follow instructions. There is some magical connection between people who want their pH to 'magically' stay balanced and their ability to read and follow instructions. For example, if you read the label, it says to use it with water between such and such a hardness level.
Ask the folks who killed their filters and/or heater if they tested water hardness.
It also says to put the pH where you want it BEFORE you 'lock' it. Makes sense. But if you don't... it will mess up the filters a bit.
This is from the LT web page:
"As Needed:
1. Adjust pH and total alkalinity of freshly filled spa to proper levels. (pH level: 7.2 - 7.8 ppm total alkalinity level: 80-120 ppm)
2. Add entire bottle to filled spa while the filter is running.
3. pH will instantly increase or decrease to a reading between the ideal range of 7.2 to 7.8.
Tips:
Add to freshly filled water. pH Balance should not be used in hard water areas where calcium reading is above 150 ppm. In these conditions, this formula will soften hard water and release calcium into spa water possibly causing cloudy water, scaling and clogging of spa filter. If you are not in a hard water area, but experience clouding of spa water after applying pH Balance, Leisure Time recommends using Bright & Clear to return clarity to water. "
The also sell pH Balance Plus for areas with hard water...
8-)