10-year cost of ownership
One number, every line, the same model reviews use.
Every HydroAudit review scores a system against this same 10-year cost math. The slider defaults match the cohort medians we publish; drag them to match your own quotes.
Purchase price$1,800
Installation$600
Annual salt$110
Filter replacement cost (per cycle)$0
Annual maintenance / service$60
years
Total cost of ownership
$4,100
over 10 years · $34 / month
- Purchase
- $1,800
- Install
- $600
- Salt × yrs
- $1,100
- Filters (none)
- $0
- Service × yrs
- $600
Adjust the inputs to model your real install. The numbers snap to the published defaults when you pick a system above.
Year-by-year breakdown
10-year cost curve
Stack composition: salt · filters · service · install · purchase.
PurchaseInstallSaltFiltersService
| Year | Purchase | Install | Salt | Filters | Service | Total | Cumulative |
|---|---|---|---|---|---|---|---|
| 1 | 1800 | 600 | 110 | 0 | 60 | 2570 | 2570 |
| 2 | 0 | 0 | 110 | 0 | 60 | 170 | 2740 |
| 3 | 0 | 0 | 110 | 0 | 60 | 170 | 2910 |
| 4 | 0 | 0 | 110 | 0 | 60 | 170 | 3080 |
| 5 | 0 | 0 | 110 | 0 | 60 | 170 | 3250 |
| 6 | 0 | 0 | 110 | 0 | 60 | 170 | 3420 |
| 7 | 0 | 0 | 110 | 0 | 60 | 170 | 3590 |
| 8 | 0 | 0 | 110 | 0 | 60 | 170 | 3760 |
| 9 | 0 | 0 | 110 | 0 | 60 | 170 | 3930 |
| 10 | 0 | 0 | 110 | 0 | 60 | 170 | 4100 |
How the math works
The model expands an arbitrary ownership window (default 10 years, capped 5–15) into one row per year, then folds the rows together. Every cost line is a slider you can override.
- Year 0
- Purchase + install land in the install year only.
- Salt
- Recurs every year the system uses salt.
- Filters
- Hit the years divisible by your cadence (1, 2, 3, 5).
- Service
- Recurs every year (scheduled maintenance).
- Cumulative
- Running sum across the ownership window.