More people are getting to discover the joy swim can bring as well as it’s amazing avenue for exercise. However, as people get to build more pools, about 70% of new pool owners go for salt water pool systems. It is not outrageously expensive, healthier and a good investment in the long run.
A major problem they do have to worry about is corrosion. Corrosion of salt water pool can be likened to a cancer, it slowly destroys decorative parts and structure of the pool area and can also be harmful to swimmers. Arguably, the biggest problem for many owner of salt water pool is corrosion.
Salt itself is a corrosive mineral but it takes years before any real damage can occur, most corrosion in pools are as a result of electricity reacting with salt water minerals to speed up the process.
How do you know if your salt water pool has corrosion? To prevent corrosion and it’s effects on your pool, you need to know first, how to identify if your pool is corroded.
How does Corrosion Occur?
The process of corrosion starts with a normal chemical process known as electrolysis which leads to galvanized corrosion at a very fast rate because of the ions in the saltwater. The amount of salt in the water and stray current available is directly proportional to the corrosion rate i.e. the higher the salt content, the faster corrosion occurs. This is why it is important to check salt concentration often.
At first you notice the decorative parts of your pool and its stainless light reams changing color. Some exhibit the golden brown color characteristic of a rust, while the shiny silver parts of some start to wear off gradually.
Knowing the reason why corrosion can happen in a salt water pool is half the problem as it helps to know what to do to prevent it from happening.
The main possible causes of the corrosion are:
- Rust plaiting: Occurs when there is too much metals inside the pool.
- Bad water chemistry with high concentration of ions in the water. This is why it is important to do all necessary testing before use of the water in a pool.
- High level of salt concentration in the pool: You can always prevent this by checking the salinity of your pool using sodium chloride test strips. If the salt concentration level in the pool seem high you should get a professional to reduce it.
- Wrong lightning system and electricity for the pool area.
- Low chemical levels in the pool e.g. low alkalinity levels, low PH levels, low calcium levels etc.
- Improper grounded pool or a combination of any of the above.
Corrosion Prevention Methods
Adjust Salinity of Pool
Ensure the salinity of your pool is at the average concentration and ensure drainage and refill of the the pool at an interval of at least 6 to 8 years. You should however review the salinity and salt cell concentration every month and ensure proper cleaning at least three times a year.
Seal the Porous Surface
You can also proceed to seal any porous surface which would get constant exposure to the pool to prevent damage caused by rust in the long run.
Another fool proof method to prevent corrosion in your salt water pool is the use of a sacrificial zinc anode or a less common magnesium anode. When a zinc anode is installed, all the electric charge that affect metals and structures around your pool are now drawn to the anode. Over a period of time, the materials in your pool stop being corroded as the zinc anode is sacrificed instead.Zinc is one of the most active metals in reference to voltage, this makes it’s decomposition faster before damages can be done to surrounding metal elements in the water such as ladder,heaters, steps, filters e.t.c
The chemical process known as electrolysis (oxidation and reduction) occurs of the zinc instead of these metallic elements and the protective nature of zinc does not allow the process go past the metal of the anode even while break down or decomposition occurs.
A zinc anode lasts about 6 to 9 months before a replacement is needed. All swimming pools must have a sacrificial zinc anode installed but this is especially important for salt water pools because of the fast galvanized corrosion process due to its ten times content of salt compared to regular chlorine pools.
Another safe method to protect your pool from corrosion is proper bonding. Ensure a bonding wire or grounding plate is installed on the fence to practically reduce rate of rusting. Keep the bonding site as close to the pool as safely possible. Bonding is the process of connecting all electrical implements related to the pool to have the same electrical potential. This keeps the potential voltage among all electric equipments relatively the same which reduced the rate of electrolysis that occurs. This does not completely eliminate corrosion of the salt water pool but it reduces it by a long shot
You should ensure that bonding and the installation to the sacrificial zinc anode is done by only professional electricians.
Closeness of Different Metals
Another factor that greatly affects the rate of galvanized corrosion is the closeness of different metals. The closet they are, the higher current transfer is. So instead of bolts and nuts of the different metal parts of your pool being steel or iron, you should replace them with sacrificial zinc anode to further reduce rate of corrosion.
As the old adage goes, prevention is better than cure, salt water corrosion is not something you can easily identify, it often takes an obvious rusting of pool parts, wear and tear of the stones or even damage of pool equipment before many pool owners start to notice. The best option is for prospective and current owners of saltwater pool is to clean up the water regularly and check the salt content often as well as consider any of the protective options above. If you however notice rust already, ensure to contact only a professional pool cleaning service to avoid more damage to your property.