Macherey-Nagel test strips for carbonate hardness, in one presentation.
91323
A semi-quantitative test strip for carbonate hardness, the water's buffering capacity. Dip it, wait the stated time, and compare the pad against the colour scale on the tube.
Carbonate hardness is what keeps pH from swinging. An aquarium or a pond with none of it can crash from safe to lethal pH overnight, and no amount of pH adjustment holds until the buffer is restored.
A strip gives a range, not a figure. That is enough for the great majority of decisions — dose or do not dose, discharge or hold, keep running or stop — and it gives the answer where the sample is, in about a minute, with no instrument to calibrate and nothing to carry back to a laboratory.
When a number has to be defensible — a regulatory report, a dispute, a limit you are close to — a photometer or a laboratory method is the right tool. The strip's job is to tell you whether you need one.
If pH will not hold where you set it, measure carbonate hardness before dosing more acid or base — the buffer is usually the real problem.
Supplied in one presentation.