Every sheet here stays free. Buying the workbook, or giving whatever you think this has been worth, is what keeps it that way.
Twenty-one design sheets: pipework and pumps, four routes to solids separation, media and carbon filtration, iron and manganese removal, ion exchange, the whole membrane range from microfiltration to reverse osmosis, continuous electrodeionisation, UV disinfection, heat transfer, chemical reaction tanks, and sludge dewatering by decanter centrifuge and filter press. Each sheet gives the governing equations, the design envelope industry practice actually accepts, and a calculator that recomputes as you type — so you can size a train in the browser before you open a spreadsheet.
The full method, the equations and the calculators stay open. If a sheet saved you an hour, the most useful thing you can do is share it with the engineer who needs it next.
Share this page on LinkedInEvery sheet on this page as a linked Excel workbook — every formula visible, unit-consistent, with water properties computed from your temperature rather than assumed. Change the plant flow once and every sheet that depends on it follows. Includes a summary tab, an equipment list and a revision-controlled calculation record for design submissions.
SGD 19.90 until 31 December 2026 — both files, one payment. It doubles to SGD 39.90 on 1 January 2027. Currently v1.6. Buy once and every version after it is free — see the version history.
The workbook goes further than this site does. Every sheet here stays free — nothing moves behind a paywall. But future releases of the file carry unit operations and reference material the free pages do not, and new equipment lands in the workbook first. Every one of those versions is covered by the same one-time price.
Anything at all — something on this site, the workbook, a project, water treatment in general, or getting into the field. Pick a subject, write the question, and it reaches me directly.