Softener Capacity (grains) = Max softener capacity in gallons Įxample: 180,000 grains = 26,087 gallons Ī 10% Safety Factor is applied to prevent hardness from breaking through.Įxample: 26,087 gallons X 0. Total Hardness (ppm) = Total Hardness (gpg) Example: 118 ppm TH = 6.9 gpg įt3 resin X resin exchange capacity (typically 30,000 grains/ft3) = Grains capacityĮxample: 6 ft3 resin X 30,000 grains/ft3 = 180,000 grains of capacityģ. Convert water hardness from ppm to grains per US gallon The softener capacity is calculated in three simple steps:ġ. See Softener Regeneration with Salt Saver Dosages (TB4-006).Įach calculation is followed by an example, using this information: The water contains 118 ppm of total hardness and the softener has 6 ft 3 of resin that is regenerated using 15 lbs of salt per ft 3. Lower salt dosages reduce capacity, but allow for more economical salt usage, which is the basis for salt saver dosage.
The degree of hardness is expressed as parts per million (ppm). The hardness of water is calculated in terms of the weight of C a C O 3. Typically, a salt dosage of 15 lbs/ft 3 resin is used to provide an exchange capacity of 30,000 grains/ft 3 resin. Water hardness is measured in either grains per gallon (GPG) or parts per million (PPM), but you don’t have to do complex mathematics to know if your water is hard. Hint: Here, the hardness of water is permanent. The salt dosage during regeneration determines the resin exchange capacity. If the resin volume is unknown, Table One can be used to cross-reference the tank circumference and height to the resin volume.
Calcium carbonate is not responsible for the hardness of the water. Boil it to precipitate Ca- and Mg-bicarbonates as calcium carbonate and magnesium hydroxide. Any water with a PPM over 200 can be considered hard water. Hard water is classified by the high levels of calcium and magnesium present, but there can be other minerals in the water as well. Problem-4: Calculate the amount of temporary and permanent hardness of a water sample in Degree Clarke’s, Degree French and Milligrams per Litre which contains following impurities. This water will clean with some efficiency, but may leave light yellow spots on laundry or a thin white or oily film on hard surfaces after using it. Moderately hard water is still safe to drink, but it may leave behind a slightly unpleasant taste. The hardness of water is calculated in terms of the weight of $CaC$ is chosen as the standard for calculating the hardness of water because its molecular weight is 100 and this makes it easier to do the calculations. Standard Hard water (at pH10) Vs EDTA (EBT indicator wine red colour to blue colour) M 3 M 4 M 2 Hardness M 3 x 100000 ppm Step5: Estimate the permanent hardness of unknown water sample: Pipette out a known volume of hard water sample (V 5 ml). Hard Water is water that contains a high mineral content. Hard Water: The water which does not give lather with soap is called hard water. Moderately hard water has between 75-150 ppm of minerals dissolved in it. Hint:Here, the hardness of water is permanent.