Bromine reading = chlorine reading × 2.25. A test that reads 2 ppm on a chlorine scale means 4.5 ppm bromine.
4.51ppm
bromine
2 ppm on a chlorine scale = 4.51 ppm bromine. Bromine weighs 2.25 times as much as chlorine per unit of sanitizing power (159.8 ÷ 70.9).
| Chlorine | Bromine |
|---|---|
| 1 ppm chlorine | 2.3 ppm bromine |
| 2 ppm chlorine | 4.5 ppm bromine |
| 3 ppm chlorine | 6.8 ppm bromine |
| 4 ppm chlorine | 9 ppm bromine |
| 5 ppm chlorine | 11.3 ppm bromine |
Save this test and get a reminder before your next soak.
Spa Calc for iPhoneComing soon to the App StoreDPD tests measure oxidizing power. One molecule of bromine (Br₂, 159.8 g/mol) has the same oxidizing power as one molecule of chlorine (Cl₂, 70.9 g/mol), but weighs 2.25 times as much. Since ppm is a weight, the same color reads 2.25 times higher in bromine.
4 to 6 ppm, never above 8 ppm to soak.