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Why is My Pool Turning Black When Using an Ioniser


A swimming pool ioniser cleans and sanitizes pool water by releasing positively charged copper and silver ions into the water to destroy algae and bacteria.

Even though ionisation is a proven method for destroying unwanted bacteria and viruses, it's generally not as effective as chlorine alternatives. Pool ionisation still requires you to shock your pool with chemicals on a frequent basis.

Pool ionisation can lead to staining on a pool's interior surface or liner.

When copper ions attach to the pool's liner, the result is an aquatic blue-green stain. The discolouration is especially noticeable on pools that have a white or light-coloured lining. Copper ions can also turn blond hair green. As silver ions react to sunlight, they leave black stains on interior pool walls. A proper pH balance and use of a sequestering agent, such as a stain and scale remover, can reduce or eliminate ionisation staining. If you have hard water and your calcium level exceeds 500 parts per million, you should clean your ioniser's electrodes frequently to remove scale deposits

Pool Ionisers don't neutralize organic materials, such as body oils, natural suntan lotions, pollen, dirt or urine.

As a result, the level of total dissolved solids, called TDS, must be tested on a frequent basis -- generally every week. In a properly chlorinated pool, TDS levels typically only need to be tested two or three times during an entire swimming season. For pool ionisation to work properly, a pool's TDS level must remain below 1,000 parts per million

The release and dispersion of copper and silver ions with a pool ioniser is a slow process.

It takes time for ionisers to adequately and sufficiently dispel ions throughout the water. In general, the greater the volume of water in the pool, the longer the ionisation process. An ioniser's voltage is also a factor; high-voltage systems operate more rapidly. It can take several hours for released ions to kill bacteria, algae and other contaminants in the water.

Pool ionisers must be used in conjunction with chemical sanitizers.

Even though ionisation decreases the amount of chemicals you need to clean a pool, some chemicals are still necessary. You must shock your pool water with chlorine, bromine or another acceptable chemical as recommended for the volume of water in your pool. If you run your pool ioniser continuously, you'll likely need to shock your pool once a week. You won't need floating chlorinators or chemical dispensers. Shocking the water on a weekly basis can lead to chemical stains on the interior of your pool. If your pool water exceeds 26 degrees, the ionisation process is less effective, and more chemicals may be required to keep the water clear

If the pool has black or brown stains, this can be caused by high mineral levels--such as iron--or by insufficient chlorine levels. The best way to deal with this is to add a stain remover to the water.

While pool ionisers do fight organic matter like algae, they’re not the best oxidisers, so they’re not completely effective on their own. To get full sanitisation, you’ll need to supplement your pool ioniser with chlorine. You can use either liquid chlorine or tablets, whichever you prefer.

The good news is because a pool ioniser does reduce the number of contaminants in your pool, you won’t need nearly as much chlorine as you would if it were the only sanitiser. Rather than the standard 1 part per million (ppm) to 3 ppm, if you’re using a pool ioniser, the chlorine level only needs to be somewhere between 0.5 ppm and 1 ppm.

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