Bromine is a pool chemical that acts as a sanitiser, and has been a popular alternative to chlorine. Bromine lacks the strong smell and the potential for skin irritation that chlorine has, but it is still important to monitor bromine levels in the pool to make sure that they are not too low and not too high.
What is Considered High?
The bromine level for a pool is generally between 2.5 and 4 parts per million (ppm). High is considered any higher than this, although it is generally not considered inappropriately high until it reaches levels of 5.5 parts per million. Once the levels reach more than 7.5 parts per million, the course of action for lowering levels will change. Because the levels of bromine in the pool will fluctuate quickly, test the pool at least every few days while it is open and running. During time of high use and evaporation, it may be necessary to test every day to make sure the levels are still acceptable.
There are many environmental factors that will lower bromine on its own, so if the levels are high without being extremely high -- between 4.0 and 5.5 parts per million -- stop adding bromine for several days, and continue to test the water to see if the levels go down. For extremely high bromine levels, it may be necessary to partially drain the pool and refill it with fresh water.
When bromine combines with any ammonia that is in the water, it leaves residue behind in the form of compounds called bromamines. These compounds will continue to build up, and will need to be removed by applying another chemical called shock. This can be done on a regular schedule that is determined by the size of the pool and environmental conditions.
Impact of Environment
High bromine levels are a much rarer problem than low levels because of the environmental factors that impact the use of bromine. Bromine is used up when it attacks and kills a wide range of contaminants from bacteria and algae to dirt. Hot weather and high humidity can cause the levels of bromine to drop quickly, and rain can dilute the water in the pool to lower levels. During high-use times, bromine levels will also drop quickly. Because it is used up so quickly in so many different ways, environmental factors will do well in lowering the bromine levels without adding more chemicals to the water.
Dangers of High Bromine
Bromine does not have any of the harsh side effects of chlorine, but when you add bromine to the pool you're also adding chlorine. Typically, each bromine tablet contains about 28 per cent chlorine; therefore, when the bromine level is high, the chlorine level is high as well. While bromine itself is usually used because it is easier on the skin and eyes, high bromine levels can lead to the skin irritation and the strong smell that goes along with chlorine.