These calculations are based on a known FLOW RATE of water through the Dechlorinator and a known FEED RATE of dechlorination solution(mixture of Vita-D-Chlor and water) into the Dechlorinator

ROMAC deChlorinator VITA-D-CHLOR Calculator 1

Enter the three parameters and click "Calculate".
Flow Rate in GPM       
PPM of Chlorine      
Feed Rate in GPH      
Pounds per Gallon of Vita-D-Chlor   
Grams per Gallon of Vita-D-Chlor   

Pounds of Vita-D-Chlor per gallon of water = (Flow x PPM) / (750 x Feed)
Grams of Vita-D-Chlor per gallon of water = (3 x Flow x PPM) / (5 x Feed)

Flow=Flow rate of water through the device in gallons per minute (GPM)
PPM=Parts per million of Chlorine to be treated
Feed=Feed rate of dechlorination solution into the Dechlorinator in gallons per hour (GPH)