If you have a concrete or plaster pool keep the level between 200 ppm and 275 ppm.
Calcium hardness vinyl pool.
Dip the test strip dip the calcium hardness test strip into the pool water.
If calcium hardness goes above 400 ppm you will likely see a white flaky crust on the liner and pool equipment.
If your pool has a vinyl or fiberglass liner the calcium hardness level should be between 175 parts per million ppm and 225 ppm.
A low level can result in foaming which is unpleasant but shouldn t harm the liner.
But what it depends on isn t that difficult.
If a vinyl liner s calcium level is too low this soft water situation could lead to foaming and other water problems and can harm the vinyl.
For vinyl pools calcium should be between 150 250 ppm.
Fortunately calcium hardness changes rather slowly so a once a month testing and adjustment should be all you need.