Salt Pure® vs. Salted – Liquid Chlorine Systems

In Blog, Salt by Aaron Donohue

People have asked me, “Do I really need to put all the money into a salt system or can I just throw salt in and use liquid chlorine? It’s the same thing isn’t it?”

The answer is… No, they are not… the last similarity they share is that they both introduce a sodium hypochlorite to the system. The analogy I like to use to describe the (dis) similarities would be like the (dis)similarities between an FA18 Fighter jet and a Boing 747. Yeah, they are both jets, and yeah, they both fly people from one point to another, but the method and purpose are totally different..

The sad part of this though is that I know they were not always kidding. So, for those who think that throwing salt into a pool does the same thing as running a Salt Pure® system, let’s discuss the differences.

Active Strength:

The first key difference is the chlorine itself, traditional chlorine or liquid chlorine is a pre-packed product, produced in a factory, bound up with agents like caustic soda and lye and suspended in water to allow it to be both “Shelf stable” and “safe to handle”. This results in an end product with a maximum strength of around 12-13% sodium hypochlorite.

Salt Pure® generated chlorine is free of these additives and always has an active strength of around 100% pure sodium hypochlorite.

pH Level

Liquid chlorine has a pH of around 13, where the solution created in a Salt Pure® cell comes out at around an 8.

This means that with liquid chlorine you are going to end up with higher pH, rising faster.

This will require more acid or CO2 to maintain proper balance levels.

With the Salt Pure® system, your pH increases will be slower and lower.

This keeps chemical costs down, and the water more stable.



The third area that differentiates the two is price, not entirely surprising, and by now, probably expected! Liquid Chlorine systems are cheaper up front, but over the course of years, will become more expensive both directly (per gal. of chlorine, delivery fees, etc.) and indirectly (in chlorine gas damage to the pump room/storage room, pH control chemicals, etc.) The Salt Pure® system has a higher up front cost, but over the course of years becomes the cheaper option.     There are also a few misunderstandings about Salt Pure® systems, so I’ll clear them up a bit;

  • A chlorine generator is NOT an infinite source of chlorine.
  • A chlorine generator IS designed to have an expected service life, at the end of which they stop working.
  • This is one of the most common areas of misconception, so let me clarify cell life expectation a bit. Life expectancy is based on coatings, operation and maintenance;
  • Cells have special coatings to allow them to produce chlorine, and, be protected from the oxidation of the chlorine being generated.
  • Operating the cells wears on this coating, and so there is a limit to production time in hours or years (based on manufacturer testing)
  • Cells & salt systems should be “sized” with the understanding that they will need the correct operating environment (flow, salinity and voltage) and with proper maintenance (cleaning) and that they are going to be sized correctly to suit situation (not being overworked, or, cycled on/off frequently)
  • A chlorine generator IS designed to meet the demands of normal daily use over the course of the day.
  • A chlorine generator is NOT designed to handle massive numbers of swimmers all in one go (that is where backup chlorine systems come into play.)
  • Backup systems are incorporated into a Salt Pure® system for two reasons;
    • The first, because it will lower the initial cost of the system, by allowing us to size to your normal needs (because the bigger you go the more expensive it becomes.)
    • The Second, because it provides redundancy to the system (for those times when the chlorine generator is off, or when loads just get too big.)

  If you still have questions, you can always feel free to contact us and we’d be happy to provide you answers.