Buffering Capacity of Water

Definition - What does Buffering Capacity of Water mean?

The buffering capacity of water is the water’s ability to resist changes and maintain a stable pH balance even if acids or other bases are added to it.

Water with an optimal buffering ability acts like a sponge to absorb acids without altering the pH dramatically. However, when the buffering capacity of the water is exhausted, the water’s pH will start to change. If water has a high carbonate hardness (KH) level, it tends to have a higher buffering capacity.

The water’s carbonates and bicarbonates have a direct effect on the water’s buffering capacity.

MaximumYield explains Buffering Capacity of Water

Knowing a water’s buffering capacity is crucial for hydroponic growers, general growers, and anyone involved in aquaponics. In hydroponics and aquaponics the words buffering capacity, carbonate hardness (KH), and alkalinity tend to be used interchangeably.

The three terms are not technically the same but they are so closely related to the water’s pH stability and the overall results of all three are often so similar that they are virtually indistinguishable.

In order to determine water’s buffering ability, a general water KH test is used. If the water’s KH level is large, the water is highly resistant to changes in pH so the buffering capacity is considered excellent. If the KH test results fall below 4.5 dKH, the water is very unstable and the pH level is constantly shifting and the buffering capacity is extremely poor.

Share this: