Water balance can be a complicated exercise.
Simply put, it is the relationships of
different chemical parameters to each other. Your water is constantly changing. Anything
and everything directly and indirectly affects water balance - from sunlight, wind and
rain to the oil, dirt and cosmetics which may enter the water.
You will likely not change the water in your pool for many years. Continuous filtration
and dis-infection remove contaminants which keep the water enjoyable, but this is not water
balance. A pool that is "balanced" has proper levels of pH, Total Alkalinity and
Calcium Hardness. It may also be defined as water that is neither corrosive or scaling.
This concept is derived from the fact that water will dissolve and "hold"
minerals until it becomes saturated and cannot hold any more water in solution. When water
is considerably less than saturated it is said to be in a corrosive or aggressive
condition. When water is over saturated, and can no longer hold the minerals in solution;
this is known as a scaling condition. So then, balanced water is that which is neither
over or under saturated. The cliché that "water seeks its own level" certainly
applies here. Water which is under saturated will attempt to saturate itself by dissolving
everything in contact with it in order to build up its content. Water which is over
saturated will attempt to throw off some of its content by precipitating minerals out of
solution in the form of scale.
How do we know when our water is over or under saturated? First of all, we use a good test
kit (with fresh testing reagents) to measure the chemical parameters of pH, alkalinity and
on a chemical parameter to learn more: pH |
Alkalinity | Calcium Hardness
| Saturation Index