Pool, Spa & Water Treatment Chemistry worked example

Bromine Dose with spa volume basis of 2 100 gal: a worked example

This worked example runs the bromine dose numbers for a tougher week than the baseline: spa volume basis of 2 100 gal instead of the typical 4 100 gal. Estimate bromine dose from spa volume, desired bromine increase, and product yield.

The inputs for this scenario

  • Spa volume basis (gallons / 100): 2 100 gal (the input this scenario stresses; the baseline uses 4)
  • Target bromine rise (target minus current): 3 ppm (held at the documented default)
  • Product bromine yield factor: 0.17 oz / ppm / 100 gal (held at the documented default)
  • Delivery efficiency correction: 1.11 x (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Bromine dose = volume basis x desired ppm increase x product dose factor x efficiency correction.
  • Bromine dose works out to 1.11 oz at these inputs, and this is the headline figure for the scenario.
  • Base product works out to 1 value at these inputs.
  • Multiplier works out to 1.11 x at these inputs.
  • Factor A x B works out to 6 value at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where spa volume basis sits at 4 100 gal and the headline result is 2.22 oz, this scenario comes in 50% below the baseline at 1.11 oz.
  • Use it when a test shows bromine below the 3-5 ppm target, before a spa is used, or when reactivating a bromine bank after shocking. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Bromine dose: 1.11 oz (headline result)
  • Base product: 1 value
  • Multiplier: 1.11 x
  • Factor A x B: 6 value

Run it with your numbers

  • To rerun this with your own numbers, open the live Bromine Dose calculator, set spa volume basis to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.