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Problem Solver - August 2011

Simplify Chlorine Generation

Swimming pools need chlorine. This is just a simple fact. Even with the newest supplemental systems like UV and ozone, you are still required to keep a residual of free chlorine in the pool.

Traditional forms of chlorine (Cal-hypo, bleach and trichlor) are used extensively throughout the world with success, but many facilities are looking for easier, more sustainable options.

On-site chlorine generation can be the answer, but be aware of what you are buying, as some systems will cause you more headaches than they are worth.

Q: How does on-site chlorine generation work?

A: Liquid chlorine (bleach) is produced on-site when salt and water are introduced into an electrolytic cell. This process produces sodium hypochlorite (bleach), which can be stored in a holding tank, or used directly to sanitize the pool water.

Q: What should we look for in an on-site chlorine generator?

A: One of the facts of producing chlorine on-site is that for every gallon of chlorine you send to the pool, you send 1.5 to 3 pounds' worth of salt (it differs by manufacturer) with it, so the concentration of salt in the pool can increase to levels not wanted.

Make sure that the generator you select re-uses the pool water as part of its process. This way, all the salt sent to the pool will be re-used by the generator, and salt levels will not increase dramatically. This will also decrease your salt costs over the years.

If the generator you are considering uses a water softener as part of its process, beware. Water softeners not only remove the calcium from the water (calcium is required in commercial pools to protect the pool's surface), but they have to "dump" frequently as part of their operation, which uses even more salt. A chlorine generator that uses fresh water and a water softener as part of its process is not a good idea for a commercial swimming pool.

Q: How does chlorine generated on-site differ from bleach that we currently use?

A: On-site-generated chlorine is the same as the bleach you buy. It's actually better, as it's more stable and doesn't degrade as quickly as traditional 10 percent to 12 percent bleach. With traditional bleach, you send 2 to 3 pounds of salt to the pool with every gallon of bleach you add. The same is true for on-site-generated chlorine.

Q: What is the pH of on-site-generated chlorine?

A: Chlorine generated on site has a pH of roughly 9.3, which is lower than traditional bleach. Therefore, you will use fewer pH reducing chemicals. Keep this in mind when you are running a cost comparison between traditional chemicals and on-site-generated chlorine, as your pH reducing chemicals can be reduced by as much as 50 percent. Some generators have the ability to product pH neutral chlorine on site.

Q: Why should we consider an on-site chlorine generator for our facility?

A: As the cost of traditional chlorine increases and safety concerns over chlorine storage continue to be an issue, producing chlorine on-site can be a sustainable, cost-effective solution for your facility.


ChlorKing Inc.: 800-536-8180