Here is a quick method for estimating resin throughput capacities from conductivity in micromhos/cm.
Assumptions:
1. PH = 6 to 8
2. Each ppm as Calcium Carbonate (CaCO3) = 2 micromhos/cm, so micromho/cm divided by 34 equals loading in grains/gal. (Each grain per gallon equals 17.1 ppm as CaCO3).
3. Assume 90% of capacity is used, mixed bed endpoint is 1 megohm and two bed endpoint is 100,000 ohm.
To calculate the capacity from the conductivity reading, multiply the resin’s capacity times 34 times 1000, all divided by the conductivity.
EXAMPLES
What is the cation resin capacity of a water with 250 micromhos conductivity?
Using 90%: (36 X 34 X 1000)/250 = 4896 gallons per cubic foot CG8-H
What is the anion resin capacity of a water with 250 micromhos conductivity?
Using 90%: (23.5 X 34 X 1000)/250 = 3196 gallons per cubic foot SBG1-OH
What is the mixed bed resin capacity of a water with 250 micromhos conductivity?
Using 90%: (12 X 34 X 1000)/250 = 1632 gallons per cubic foot MBD-10
1. A grain is an archaic way of expressing weight. 7000 grains = 1 pound 17.1 ppm (as CaCO3) = 1 grain/gallonResins are rated in thousands of grains per cubic foot (or kilograins - kgrns)
2. The conversion from eq/liter (or meg/ml) to kilograins/cu ft is 1 meq/ml = 21.8 kgrn/cu ft