The Chloramine problem is one that swimming pools have grappled with for a long time, especially the busier indoor ones. Chloramine production is responsible for the characteristic Chlorine odor. It causes irritation to the skin and eyes and swimmers even get asthma.
So what is Chloramine and how is it produced?
As most of us know, addition of Chlorine is an important way to keep swimming pool water clean. Water chlorination helps to prevent pathogens from infecting the pool.
Chloramine is a close chemical relative of Chlorine. It is formed when free chlorine reacts with organic material. Unlike the common misperception of too much chlorine leading to the formation of Chloramine, it is actually the opposite.
Chloramine is formed when the concentration of free Chlorine is insufficient or too little.
Free chlorine kills germs and helps prevent the spread of waterborne bugs. It also oxidizes natural waste products from swimmers, including sweat and body oil. If the free chlorine levels are insufficient to oxidize these nitrogenous wastes, the free chlorine combines with them to form noxious Chloramine compounds.
How can I stop Chloramine from forming?
Well, this is a tough one as all aspects of swimming pool maintenance come into play. In fact, most experts agree that despite all efforts possible, over time Chloramine formation is inevitable.
Indoor pools accumulate more Chloramines than outdoor ones, as the air is often re-circulated, leading to a build up over time. If you can increase the frequency of fresh air circulation in indoor pools you should be able to reduce the Chloramine accumulation.
Another simple method is to strictly enforce a pre pool shower policy. The shower will remove sweat and body oil, reducing the organic load in the pool. Of course, the sweat produced in the pool while swimming is unavoidable.
Shocking the system with an excess of Chlorine is also an effective way of preventing Chloramine formation. This is generally done by adding 10 times the chlorine to the pool.
It may also help to slightly overestimate the number of people that will be using the pool, while calculating the chlorine needs.
How do I know if excess Chloramine has formed in my pool already?
When chloramine levels become troublesome (0.3-0.5 parts per million (ppm)), people begin to complain of irritation, and the odor is obvious. Chloramine in water also shows a distinctive greenish tinge.
Additionally, there are a number of test kits available, to test the level of Chloramine in water. These kits give you clear indication when the chloramine levels have reached the point that you need to take action.
One disadvantage with some of these test kits is that they measure the level of free chlorine along with the presence of Chloramines. This will lead to false positive results.
How do I get rid of Chloramine in the pool?
Getting rid of Chloramine is not an easy task, although a number of methods are offered out there as a solution to the problem. But be aware that prevention is always better choice.
Some of the methods available are:
- Superchlorination method or the shock method – this appears to be the best one available. Now, to achieve this superchlorination level you will need to administer a mega dose of chlorine to the water. It may seem counter intuitive. But it method works. A good way to ensure your administered dose is sufficient is to increase the chlorine levels to 3-6 times the normal level. This will leave your pool with about 5-10ppm of Chlorine. This is easily tested by a digital colorimeter. Maintain this level for four hours to ensure that total oxidation and destruction of chloramine.
- This method may not work against organic Chloramines. In such cases an organic agent, monopersulfate based oxidizers, can be used. The most commonly used is potassium peroxymonosulfate. About a pound of this chemical will need to be added per 10,000 gallons of pool water. Also, as a rule of thumb, it is always better to add a little extra than a little less if you are not sure. The chemical is easy to get hold of with Pool BasicsTM available for 89.99 $ on Amazon, home delivered.
- Addition of activated carbon to the existing filter system will help remove the ammonia from the system which forms chloramines.
- Adding volcanic ash to the sand filters is one option. This will prevent the ammonia from entering the swimming pool. Zeolite can be used instead of the volcanic ash sand but it needs to be regenerated over a period of time. ZeoSandTM is easily available at most online retailers and so is not difficult to obtain.
- Granulated Activated Carbon (GAC) filters can also be added to the filtration systems. Doulton USAR provides a high quality filter. The OmnifilterTM is also a cheap and effective filter that can be used. These filters vary in prices but are available for as low as $15 if you hunt around for a good bargain. The end result of these actions is to prevent the chloramine forming ammonia to accumulate in the swimming pool.
- There are UV systems that can be installed, which claim to break down the Chloramine into harmless products and also provide additional disinfection power without the use of chemicals. BarrierTM from Siemens is a respected brand with proven efficacy, however there a number of others such as Emperor Aquatics’s UV safeguard system and Aquionica UV systems that are easily available too.
- Chloramine contaminated air (responsible for the odor) is heavier than normal air and sticks close to the swimming pool surface. This can lead to a situation referred to as ‘short circuiting’. This is a situation in which only the lighter, easier to move air is circulated by the HVAC. This is basically a waste of energy and resources as only the clean air is being re-circulated without improving the air quality.
One way to prevent this from occurring is to let in a huge blast of fresh air to force the contaminated air to move into the HVAC. Devices are available in the market, which can be installed around the swimming pool and help to remove the chloramines laced air.
This has the dual advantage of improving air quality and also lessening the energy requirements of HVAC system. All of this translated to higher user satisfaction and money saved to the operator.
Draining the pool and cleaning it will help resolve the problem. Another thing to remember here is that a lot of the water is chlorinated at source and this may contribute to the overall problem of Chloramine contamination. Such a situation is difficult to tackle and will require a filter to treat the water before it enters the swimming pool.
This problem seems insurmountable.
Well, the problem is difficult but not insurmountable by any means. However, it does require cooperation from everyone including the swimmers, pool operators, pool chemists and even the people handling the ventilation systems.