Corrects Low Calcium Hardness

Fi-Clor Hardness Increaser is for raising the calcium hardness level in swimming pool water. Calcium hardness is the amount of dissolved calcium and magnesium in pool water. If there is insufficient dissolved calcium, the water will try and take it from the grouting and concrete in the pool. High levels are not a major cause for concern provided the pH and alkalinity are within recommended parameters, but the reading should be kept below 1000mg/l (ppm) if possible.


Calculate the volume of water in your pool (if in doubt, consult the Fi-Clor Swimming Pool Handbook).

Take a calcium hardness reading using your test kit. You will need to correct the calcium hardness if the reading is below 175mg/l (ppm) for liner pools, and below 250mg/l (ppm) for tiled pools.

With the circulation system running, sprinkle the product directly into the water around the perimeter of the pool. Do not pre-dissolve as this could generate excessive heat. Only use when bathing has ceased, and avoid areas near the skimmers.

Re-test after 24 hours. If the calcium hardness level is still below 175mg/l (ppm) for liner pools, and 250mg/l (ppm) for tiled pools, repeat the dose.