Water hardness in Smyrna
3.8 gpg moderately hard
Tap water in Smyrna is moderately hard: 3.8 gpg (65 mg/L · 3.6 °dH · 6.5 °fH).
Source: Town of Smyrna 2025 Consumer Confidence Report (2025) · data checked 2026-10-20
Range across supply zones: 55–75 mg/L.
The Town of Smyrna's 2025 report states a target of 55 to 75 mg/L (3.2 to 4.4 gpg) for finished water. This is a treatment setpoint, not a measured sample, so the 65 mg/L we show is the midpoint of that range. Actual tap values can differ from it. At this level water is moderate, and scale builds up slowly.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 3.8 gpg |
|---|---|
| Utility | Town of Smyrna Water System (Water Treatment Plant) |
How Smyrna compares
- Tap water in Smyrna is 58 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1160 of 1372 in the United States (1 = hardest); 15 % of these cities have softer water.
- In Tennessee it is number 5 of 9 cities; the regional median is 3.8 gpg.
- Nearest city with clearly harder water: Franklin, 32 km away (9.8 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Smyrna
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 4 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Smyrna water hard or soft?
It is moderately hard: 65 mg/L as CaCO₃ (3.8 gpg, 3.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Smyrna safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Smyrna water?
3.8 gpg, equal to 3.6 °dH, 6.5 °fH or 65 mg/L calcium carbonate.
What dishwasher salt setting should I use in Smyrna?
For 65 mg/L (3.6 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Smyrna?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Town of Smyrna 2025 Consumer Confidence Report (2025). Method: computed from supplier's calcium and magnesium. Town of Smyrna 2025 Consumer Confidence Report · Outdated figure? Tell us