Almost every dosing error is a units error. The dose is set in milligrams per litre of water, the pump is bought in litres per hour of solution, and between the two sit a strength and a specific gravity that are easy to apply upside down. This page carries the chain through once — and then answers the two questions a drawing has to answer anyway: what size is the pump, and how often does somebody refill.
The three calculators on this page — dosing rate, day tank storage and the polymer preparation unit — are part of a subscription, along with every design sheet.