When choosing a softener tank size, it is important to know a couple of things:
  1. Hardness of existing water (in PPM or Grains)
    2. Approximate demand flow (gallons per minute)With these two components, you can determine approximate daily flow of your softener system and the amount of capacity necessary in a softener tank to last at least 24 hours.Below, fill in the approximate hardness value and demand flow for your desired system.With the KiloGrains of hardness / 24 hrs, you can compare to capacity of different size tanks. Choose a Tank size that has minimally the calculated KiloGrain value in the calculator.

Resin Tank Size
Capacity, Kilograins Cubic Feet Bed Height (inches) Diameter (inches)  FRP Tank Height (inches) Metalic Tank Straight Wall Height (Inches) Slow Rinse (gpm) Back Wash (gpm)
150 5 34 18 65 N/A 2.5 10
210 7 35 21 62 N/A 3.5 15
240 8 40 21 62 N/A 3.5 15
300 10 38 24 72 60 5 20
450 15 37 30 72 60 5 20
600 20 34 36 72 60 7 30
750 25 42 36 72 66 7 30
900 30 37 42 72 60 10 45
1050 35 44 42 72 66 10 45
1200 40 38 48 72 60 12 60
1500 50 38 54 N/A 60 15 80
1800 60 45 54 N/A 72 20 80
1950 65 40 60 N/A 60 20 100
2100 70 43 60 N/A 66 20 100
2400 80 40 66 N/A 60 24 120
3000 100 42 72 N/A 66 26.2 140
3600 120 43 78 N/A 66 31.3 165
4200 140 44 84 N/A 66 37.9 190
4800 160 43 90 N/A 66 40.9 220
5400 180 43 96 N/A 66 47.9 250