Coagulant Dosing Calculator
The coagulant dose is not a design constant. It is whatever your jar test found on the water you have, and it moves with the source, the season and the raw-water change. So the dose is your input, not a default here. What this calculation does is convert it: from the dose you measured, and whether you measured it as active metal or as product, into the active metal and the product mass you actually have to buy and make up.
Design parameters
State the dose basis you measured. The same number means very different things as active metal and as product — at an 8% active content, 10 mg/L of metal is 125 mg/L of product — so the basis is not a detail.
Basis and limits
- Active content is the fraction of the product that is the metal itself. It is not the oxide percentage that appears on a datasheet — for alum, the Al₂O₃ figure and the Al figure differ by a fixed ratio, and using the wrong one mis-states the dose.
- The safety factor applies to the active metal and to the product together, so the two figures cannot disagree about it.
- No coagulation pH is predicted. The pH after dosing is a jar-test result in its own right, and it moves with the dose.
- A coagulant dose found on one water does not transfer to another. Re-test when the source or the season changes.
Workspace
Continue where you left off
Saved calculations in this browser can be reopened with their inputs intact.
No saved calculations yet
Use the Save Result button above and your calculation will appear here for quick reload, ready to be attached to a project or included in a report.