Home water · demand first
Home water demand & filter sizing
People determine daily volume; the mix of installed fixtures estimates probable simultaneous peak flow. Then—and only after choosing a treatment medium—can we estimate the hydraulic minimum filter size.
Three different answers
Home design snapshot
How to read it: 480 L/day is consumption; 2.50 m³/h is a brief probable peak. Do not multiply peak flow by 24 hours.
Why two demand numbers?
A quiet day and a busy ten minutes are different problems.
Daily volume helps size storage and operating cost. Probable peak flow helps size pipe, pump, valve and filter hydraulics. Occupants alone cannot safely determine filter media volume.
Worked example · four people
The default form is a complete example.
Two showers, two toilets, two basins, one kitchen sink and one washer total 16 WSFU. The WQA table rounds that to 10 GPM probable demand; a visible 10% allowance gives 11 GPM (2.50 m³/h). Daily use at 120 L/person is 480 L.
- Confirm available well/utility flow.
- Test the water before choosing media.
- Check backwash flow separately.
Check the assumptions
Method and primary references
The equations are shown so the result can be checked. Product data and site conditions still govern final selection.
- WQA Residential Design (2025)Fixture weights and probable peak-demand table.
- Jurnal Permukiman · PUPRObserved Indonesian domestic water-use ranges.
From answer to equipment
Bring the duty point, not just a product name.
Watermart can check the calculation against the actual water analysis, pressure, valve, pump and installation constraints.
Discuss this calculation →Educational preliminary calculation—not a stamped design, quotation, or treatment-performance guarantee.