The companies specializing in the maintenance of swimming pools do not give the scope due to the multitude of inquiries from owners and users about the immediate future of their facilities, affected by the restrictions imposed by the drought. One of the most recent doubts is whether they can completely or partially fill their swimming pools with sea water, a possibility that has gained relevance after some company that does not specialize in swimming pools has publicly offered its services to transport sea water to the facilities that they ask The companies manufacturing components, construction and maintenance of swimming pools and the Catalan Water Agency (ACA) warn that the proposal to fill or refill swimming pools with sea water is technically very complex in the vast majority of cases and that it can be il · legal meeting the regulatory requirements.
Most swimming pools in operation are divided between those that use fresh water, to which chemicals such as chlorine are added to maintain sanitary conditions, and those that have saline hydrolysis (electrolysis) systems, which use slightly salty water (between 2 and 6 grams of salt for each liter of water) with which they generate their own chlorine.
Only a very small proportion of swimming pools have more sophisticated systems of disinfection by treatment with ozone or ultraviolet light and there are also very few located very close to the coast in which sea water is used directly, which is captured and returned to the sea with the legally established permits and conditions. For swimming pools with fresh water and added chlorine, the proposal to use sea water in whole or in part is unfeasible, point out the specialists consulted by La Vanguardia. Putting salt water in a fresh water pool disables the function of chlorine, damages the filtering equipment and causes corrosion that endangers the integrity of the installation.
In the case of pools with saline hydrolysis, the addition of sea water is also not recommended. "If we partially fill the pool with seawater we run the risk that the salt electrolysis equipment will stop working, since seawater contains 33 grams of salt per liter and the equipment works at 6 grams", details Àngel Pastor, from the technical service of Piscines Blanes, one of the leading companies in the sector.
"Sea water can cause the electrolysis to stop and damage the equipment, as well as increasing corrosion; only in specially prepared pools, such as those for thalassotherapy treatments, can seawater be used safely", explains David Tapias, Director of Innovation at Fluidra, one of the most important manufacturers of equipment for swimming pools in the world.
The ACA reminds that, although seawater can theoretically be used in swimming pools, it is explicitly forbidden to pour seawater into the natural environment and into the sewage system. This last prohibition is general and aims to avoid the technical inconveniences that salt produces in wastewater treatment facilities.
David Trias, from Fluidra, emphasizes that the ACA "makes a great effort of management and information in a situation as complex as the current one" and encourages citizens to collaborate in saving water and consult details about the drought on the agency's website.
