Calcium Carbonate Scaling
Definition
The precipitation of solid calcium carbonate on system surfaces once pH rises enough to permit carbonate, given calcium and alkalinity already present.
As pH rises past roughly 8.3 carbonate is no longer strongly suppressed, and once carbonate exists calcium carbonate becomes thermodynamically favorable. With sufficient alkalinity and calcium in the tower, scale forms relentlessly across large surface areas, and inverse solubility concentrates it on the hottest surfaces. pH is not the cause of scale, but it gives carbonate the permission needed to form it.
Related concepts
Acid Feed for Scale Control · pH (Lever) · Inverse Solubility of Calcium Carbonate
How it connects
- this drives Scale
- Supersaturation drives this
- Inverse Solubility accelerates this
- Alkalinity enables this
- Carbonate Speciation enables this
Part of The Blueprint of Water · 🧪 chemistry