Sodium Bromide, bromine reading and ph


Dec 12, 2020
I am having a hard time to maintain good water chemistry in my spa. My problem is that I find it hard to have a good and long lasting bromine reading after a couple of weeks. At the same time the pH tends to raise while the bromine salt cell generate bromine.

Within a week or two after draining the spa and refill with fresh water the water starts to look like carbonated water when the pumps are running and the water feels very hard for the bathers.

I have tried to use MPS without any significant changes. As I understood it is no need for MPS when having a cell that creates bromine. Only when bather load is high or water

Amount of water: 378 gallons (1470 liters)
Sodium Bromide: 1300 ppm
CH: 100
TA: 120
PH: 7,2
BR: 3
Phosphate: 0ppb
Iron: 0
Copper: 0
UV: disconnected
Ozone: disconnected
Temp: 101 F (38,5 C)

Any suggeations?
Last edited:


Bronze Supporter
Mar 5, 2020
Melbourne, Australia
Pool Size
Salt Water Generator
SWG Type
Astral VX 7T
Deleted. Got two threads muddled up.
Last edited:


Dec 12, 2020
Im no expert in spa but it seams its just a regular SWG. Bromine can only be converted to bromide back and forth with the aid of CL being generated by the SWG.
Yes, it is a SWG but it converts sodium bromide into bromine through electrolysis.

Anyone by chance know why I can’t get a bromine reading after a couple of weeks?
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