Salifert Kh+Ph Buffer safely increases the alkalinity and carbonate hardness in the water as well as establishing the level of pH. Within 24 hours the aquarium will acquire the pH corresponding to other aquarium parameters. Should the pH be found to be low within 24 hours of corrective measures then an insufficient gaseous exchange (inefficient aeration) is quite often the cause and the relevant measures should be taken. If used as directed, too much unnecessary precipitation of various elements including strontium, barium and magnesium is avoided. Available in 250 ml size.