By The Zagosa Team. Published .
Reviewed or updated .
A bromine reading sitting in band tells you there is enough free bromine in the water. What it does not tell you is how much organic load has piled up, or whether bromamines are starting to form. Weekly shocking in a bromine tub matters every bit as much as in a chlorine one, and it takes the same 20 minutes.
What a shock achieves in a bromine tub
Non-chlorine shock has a bonus role in bromine systems: it turns spent bromide back into active bromine. So a weekly shock refreshes your bromine reservoir on top of clearing organic load.
Skip the weekly shock and the bromide level climbs (you keep adding bromide but never converting it back), the water starts to feel slick, and the tablet feeder can no longer keep up.
The weekly bromine shock routine
Pick a regular day, ideally an evening. Dose a full bottle dose of non-chlorine shock at the per-litre rate.
Lift the cover and run the jets for 15 minutes.
Put the cover back and walk away. By morning, free bromine should have edged up and the water should feel fresh.
When to use chlorine shock in a bromine tub
Once a month, or after a really heavy session, a chlorine shock at 10 ppm reactivates the bromide pool more forcefully than non-chlorine shock and gives a deep clean. Wait until free chlorine is below 3 ppm before bathing.
Do not make chlorine shock the permanent routine. The CYA in some chlorine shock products is wasted in a bromine tub and can build TDS for no reason.
Unscented sodium hypochlorite (the same active as household bleach but in pool grade) is a clean chlorine shock for bromine tubs, because it adds no CYA.
Common questions
Will shocking push my bromine reading off the scale?
It will spike for a few hours, especially after a chlorine shock. Wait until it settles back to 4 to 6 ppm before bathing. The high reading harms the tub not at all, only your comfort.
Should I add more bromine tablets after a shock?
No, the shock reactivates existing bromide. Adding more tablets at the same time is redundant and overshoots the level for days.