Thaka.AiReviewed 16 October 2026 · schematic not to scale
A trained-construction route using the complete CAWST mould and outlet geometry. This summary and translation adapt CAWST, www.cawst.org, CC BY 3.0; use the current source manual.
- 1Covered inlet and diffuser
- 2Standing water, about 5 cm
- 3Prepared filtration sand
- 45 cm separation + 5 cm drainage gravel; protected outlet
Site and operating requirements
- Identify intended use and likely biological, chemical and salt contamination before choosing treatment. Obtain suitable water testing.
- Keep raw-water and treated-water containers, tools and hands separate. Use clean covered storage.
Tools and measuring equipment
- Graduated vessel, timer, clean handling kit, source-specific test equipment and the selected manual’s tools; trained construction for biosand.
Output and operating conditions
V10 full-reservoir flow check: about 0.4 L/min. Flow rate is not a water-safety certificate.
2012 manual: specifications p8, materials p30, media pp46–58, construction pp60–69, installation pp79–86, use pp88–95. Do not rescale to an arbitrary bucket.Parts, quantities and dimensions
| Part | Quantity | Specification / dimensions |
|---|---|---|
| V10 container, diffuser, lid and outlet | 1 set | Use manual drawings; tube 105 cm long, 6 mm ID, 9 mm OD. |
| Filtration sand | ≈30 L | Screened below 0.7 mm; prepare and wash according to manual. |
| Separation and drainage gravel | ≈3.25 L + 3 L | Separation 0.7–6 mm; drainage 6–12 mm; each installed layer 5 cm. |
Preparation and component checks
- Read the complete linked method, mark its edition, and create a measured component list and a labelled sketch before starting. Keep experimental changes separate from the published procedure.
- Prepare the work area and inspect every component. Run the lowest-risk dry or unpowered check before water, heat, moving parts or crop material are introduced.
Procedure
- 1
Obtain the complete mould drawings, training and quality-control forms before fabrication.
- 2
Sieve and wash the media separately. Cast the documented container and wet-cure for seven days.
- 3
Install level, add water, then place drainage gravel, separation gravel and sand under water to avoid trapped air.
- 4
Fit the diffuser and lid; preserve about 5 cm standing water. Flush and check full-reservoir flow against the manual.
- 5
Allow roughly 30 days for biolayer establishment. Disinfect filtered water and store covered; maintain as the manual directs.
Safety and inspection
Filtration does not remove every pathogen or dissolved contaminant. Use disinfection and safe storage; handle cement with eye, skin and dust protection.
Verify the result
Use source-water and treated-water testing with a local water specialist. Track flow and maintenance without equating faster flow with better treatment.
Measurement log
- Source identity, intended use, method/device, batch volume, time, temperatures/flow where relevant, completed treatment indication and laboratory test results.
Maintenance and repeat checks
- Inspect and clean after each trial following the source method. Record wear, contamination, leaks or loose components; do not restart until the cause is corrected.
- Use the source’s service intervals and replacement limits. Recheck the result whenever a component, material, input condition or method changes.
Troubleshooting
- Flow/cycle outside the documented range or failed test
- Do not use the output for drinking. Recheck raw-water quality, batch volume, seals/media/device status and the complete source instructions. Retest after correction.