Salt or no salt? That is the question! Or at least one of the most common questions being asked by pool owners and operators these days. Every pool owner has their own set of reasons for wanting salt or not wanting salt. There are many questions regarding the mechanical equipment at the facility, finishes of the pool, uses of the pool, local bylaws, (just to name a few) that must be answered before jumping to any decisions. Additionally, the owner must be aware of the many myths regarding salt water systems and chlorine systems alike before making any decisions. They must also understand that a salt water pool doesn’t mean you will be swimming in ocean water! Windows to the Universe team states that salt water pools typically have 3,000 to 6,000 ppm, while the ocean is about 35,000 ppm.
When changing a liquid chlorine sanitized pool over to a salt water system, or when building a pool destined to be salt water, the mechanical systems must be selected properly. Everything from the pumps, filters and heaters must be designed and approved for use in a salt water pool. If this is not done, manufacturers will not honour warranties, and there will be damaged equipment much prior to their normal lifetime.
The finishes of the pool need to be considered when contemplating a salt water pool as certain finishes do not last as long under salt water conditions. Liners, tile and plaster finishes all have their own issues when it comes to salt, so owners must investigate each option thoroughly and ensure whichever option is chosen is installed properly. As with any sanitation system, monitoring and proper balancing is also very crucial in the lifetime of the finishes.
Fixtures such as hand rails, underwater lighting fixtures, and rope anchors need to be properly chosen when going with a salt water pool as they will corrode faster without being constructed of proper materials and properly maintained. The image above shows a hand rail in a salt water pool that is rusting due to the salt. Think of what salt use on our roads does to our vehicles and infrastructure during the winter months. The same type of damage will happen to a pool that doesn’t have all of its components designed for salt water use.
Primary uses of the pool under consideration for salt water should also be considered. A pool that is primarily for lap and competition swimming where there is high swimmer volume and high exertion may want to shy away from a salt system, as it will require much more monitoring of the chlorine levels to ensure they are in accepted ranges. Yes I said chlorine. Salt water pools still have chlorine in them. They use a chlorine generator system involving a process called electrolysis to produce its own chlorine, rather than adding liquid chlorine directly to the water. A therapy pool with low patron turnover may be a better candidate for salt water, as it will be easier to keep the pool balanced and may increase user comfort.
Local bylaws are another very important item to look into when considering salt water in your pool. Especially for commercial pools, salt is typically not permitted to be the primary source of sanitation. Most municipalities still require salt water pools to have a secondary sanitation system installed, typically liquid or tablet chlorination. Furthermore, when draining the pool, salt (and chlorine) levels usually must be brought down to low levels in order to legally be dumped into the municipal sewage treatment system. Always check local bylaws for your stipulations prior to draining your pool.
Pool owners need to ensure that they do as much homework on salt water chlorination as necessary to ensure that they have made an informed decision. There are too many cases of owners not taking all of the necessary steps required to properly operate a salt water pool, and have a seemingly endless repair bill. As with any large expenditure, always ensure you are working with qualified pool designers and builders when constructing a new pool or doing a renovation, no matter what sanitation system you are going with.