Answers · Tacoma and South Sound water
Is Tacoma Water Hard Enough to Scale an Ice Maker?
The short answer
Unlikely, because Tacoma Water says its supply is softer than hard water, so a slow ice maker in the city is checked for filter, valve and pressure long before scale.
Check in this order
- Read the supplier's name on your water bill, since a house outside the city may not be on Tacoma Water.
- Replace the water filter if its indicator is lit, then throw away the first ice it makes.
- Open the refrigerator's shut-off valve fully, under the sink, in the next cabinet or in the basement.
- Freeze a tray from the kitchen tap, let a few of its cubes melt, and look for white flecks.
Past this line it is a technician's job Sub-Zero Repair Tacoma, (206) 472-1140
Behind the answer
Tacoma Water’s supply is mostly Green River water; its wells are used mainly in summer and fall.
Neither its water-quality concerns page nor the 2025 water quality report gives a hardness number for Tacoma Water’s own supply. Its one hardness row, 48 ppm, belongs to a City of Bonney Lake table for the Falling Water subdivision, on Bonney Lake water for a few days in April 2025.
Related questions
Does a Sub-Zero in Tacoma need a water softener?
Not usually for the ice maker's sake on Tacoma Water, which the utility itself compares favorably with hard-water supplies. Spend the effort on a current cartridge and a fully open valve instead. If the bin still fills slowly after that, call Sub-Zero Repair Tacoma on (206) 472-1140.
What are the white flecks left by melting ice?
Sub-Zero puts them down to calcium: minerals concentrate as water freezes and thaws, and a shrinking cube leaves them behind. They are about the water, not the ice maker. Sub-Zero suggests a current, genuine cartridge, and an in-line filter if the flecks bother you.
- Signed
- Marta Fennimore
- Role
- Refrigeration technician — ice systems and water supply
- In the trade
- 12 years
- Holds
- EPA 608 certified
- Checked
- Sep 18, 2026