Scaling Water
Scaling water has an LSI above +0.
Definition
Scaling water has an LSI above +0.3, meaning it is over-saturated with calcium carbonate and will deposit scale on surfaces and equipment.
Typical Values: LSI above +0.3 indicates scaling tendency; above +0.5 is a concern
In Plain Language
Over-saturated water deposits calcium carbonate as white or grey crystalline scale on tile lines, heater elements, salt cells, pipes, and pool surfaces. The primary causes are high pH, high calcium hardness, and high temperature. Preventing scale requires keeping the LSI below +0.3 through pH management, calcium hardness management, and the use of scale inhibitor products in borderline cases.
Why It Matters
Scale deposits on heater elements act as insulation, causing overheating and premature failure. Scale on salt cells reduces chlorine generation efficiency.
Typical Values
LSI above +0.3 indicates scaling tendency; above +0.5 is a concern
Last reviewed: 2026-06-01