Water chemistry
The parameters that describe water: pH, hardness, alkalinity, dissolved solids, conductivity, turbidity, dissolved oxygen and salinity. What each measures and how to read a value.
The combined concentration of dissolved calcium and magnesium. Hardness is the single water property most people notice: it determines whether soap lathers, whether kettles scale, and whet…
A measure of how acidic or alkaline water is, on a logarithmic scale where 7 is neutral. pH governs almost every other chemical behaviour in water — which metals dissolve, how effective di…
The total mass of dissolved substances in water. TDS is the most misunderstood number in consumer water testing, because the cheap meters that report it do not measure dissolved solids at …
The capacity of water to neutralise acid without its pH changing much. Alkalinity and pH are routinely confused: pH is the current acidity, alkalinity is the resistance to change.
The cloudiness of water caused by suspended particles. Turbidity is not itself a health parameter, but it is the most important operational indicator in drinking water treatment because pa…
The oxygen dissolved in water and available to aquatic life. Dissolved oxygen is the primary indicator of the health of a river, and its collapse is the mechanism behind most fish kills.
How readily water conducts electricity, which is proportional to its dissolved ion content. Conductivity is the quantity a TDS meter actually measures.
The dissolved salt content of water. Average seawater is about 35 grams of salt per kilogram, and the reason the sea is salty is that rivers deliver dissolved minerals continuously while e…