How Hard Water Damages Water Heaters in Marietta, GA

How hard is Marietta water?

Cobb County water sits at about 3 to 5 grains per gallon, roughly 50 to 85 mg/L of dissolved minerals, mostly calcium and magnesium. The county draws from Lake Allatoona and treats at the Quarles and Hyde Farm plants. That puts Marietta in the slightly-hard band, milder than most of Texas or the Salt Lake basin, harder than coastal Florida. Not extreme, but enough to wear a tank over years.

What that does to a tank heater

Every time the burner fires, a thin layer of calcium drops out of the water and settles on the tank floor. Over years it builds into an insulating crust. The burner now heats through stone, the steel above it cooks longer, and the anode rod gets chewed faster. Once the anode is gone, the steel pits and the tank weeps from the bottom seam.

What it does to a tankless

Worse and faster. Scale narrows the copper coils inside the heat exchanger, flow drops, internal temps spike. Most Rinnai and Navien units we see in Marietta start throwing scale codes inside 18 months without a descale. A flush every 6 to 12 months keeps them clean. Restaurants on Whitlock Avenue or near the Battery Atlanta need it more like every six.

What you can do

• Flush the tank yearly, at minimum
• Pull the anode every two years and swap when 75 percent gone
• Descale tankless units every 6 to 12 months based on use
• Consider a whole-home softener if your unit is older than 8 years
• Set the thermostat to 120 degrees F, not higher (less calcium drops out at lower temps)

When a softener pays for itself

A whole-home softener installed in Marietta runs $1,500 to $3,500. The math works out by adding 5+ years to the water heater, longer life on the dishwasher and washer, less soap, and fewer plumbing repairs from scale. Cobb County is on the milder end, so payback is closer to 5 to 7 years. The hospitality scene around Truist Park and the dense restaurant volume on Canton Street in Roswell often install softeners on commercial accounts for the same reason.