Hard-water scale is one of the top failure modes of a solar water heater. The U.S. Department of Energy warns that hard water causes "scaling of mineral deposits in the collector, distribution piping, and heat exchanger" — and recommends conditioning the water. On a pressurized solar system, scale insulates the collector and coils, so you get less hot water for more sun, pressure climbs, and the tank's life drops.

Why solar heaters are especially vulnerable

• They run hot and concentrate minerals as water heats.
• Scale on evacuated tubes/collector plates can cause superheating and cracking.
• Blocked piping and failed pumps/valves are common hard-water symptoms.

The salt-free fix

An inline conditioner keeps scale-forming minerals suspended before they reach your collector — no salt, no power, no backwash, no maintenance. Pick your flow:

Salt-free conditioners reduce and help prevent new water-heater scale; they are not softeners and do not remove existing hardness. Free U.S. shipping. See our hard water guide.