Calculate a water softener’s hardness load
Turn measured hardness and the amount of water you plan to soften into a daily grain load. Keep peak flow and operating capacity as separate checks.
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Start with hardness and softened-water demand.
The calculation you can check.
Daily load = hardness in gpg × US gallons softened per day. For 10 gpg and 200 gallons/day, the load is 2,000 grains/day. Over an illustrative seven-day interval, it is 14,000 grains. Seven days is an example input, not a prescribed regeneration schedule.
For a result in mg/L as CaCO₃, divide by 17.1 to obtain approximate gpg. A result of 171 mg/L therefore gives the same 10 gpg example. A “hard” color band without a numerical result is not enough to enter a precise load.
A grain load does not select a product by itself.
| Separate check | What to get from the proposed system |
|---|---|
| Separate checkOperating capacity | What to get from the proposed systemUsable grains at the proposed regenerant dose and settings, including the reserve approach. A nominal tank label is not the same input. |
| Separate checkService flow | What to get from the proposed systemThe documented flow and pressure behavior at the fixtures likely to operate together. Daily gallons do not establish peak flow. |
| Separate checkWater chemistry | What to get from the proposed systemIron, manganese, sediment and other relevant results. This tool adds no automatic correction factor or pretreatment recommendation. |
| Separate checkInstallation | What to get from the proposed systemSuitable space, bypass, regeneration drain, overflow provision and power where required. |
Ask the installer to show the missing step.
Keep your hardness, water-demand assumption and calculated load beside the quote. Ask how the proposed model’s operating capacity, salt dose, reserve and regeneration settings cover that load, then check service flow separately.
If the treatment goal is only scale control, settle the treatment comparison before using this ion-exchange planning calculation.