The Salt Chlorinator: How it works (technical explanation)
The two component Salt Chlorinators generate chlorine by passing low voltage electrical current through the pool water and converting the chloride ions from salt into chlorine. When salt is added to the swimming pool, it immediately dissociates to form sodium and chloride ions. NaCl Na+ + Cl. Electrical current flow is denoted at the movement of electrons (e-), which start at the negative terminal of the power supply, flow through the pool water, and return to the power supply at the positive terminal. The number of electrons leaving from and returning to the power supply is always the same. At the anode (connected to positive voltage terminal)the following reaction occurs: 2 Cl- Cl2 (gas) + 2e At the cathode (connected to negative voltage terminal) the following reaction occurs: 2 H20 + 2e- H2 (gas) + 2 OH- The hydrogen gas is not soluble in water and so it is carried along with the water flow into the pool. Sometimes, it is possible to actually see the tiny hydrogen bubbles coming out of the return jets ( a good test to see if your cell is working). At the other electrode, the chlorine gas is highly soluble in water and reacts with the water as follows: HOCl + +Cl2 + H2O+ HCl The HOCI is known as hypochlorous acid and is the primary sanitizer in the swimming pool. Whenever any type chlorine is introduced into the swimming pool, whether it be by liquid bleach, granular chlorine, gas chlorine, tri-chlor tablets, the end result is always hypochlorous acid. The function of the hypochlorous acid in your pool is two fold: first to kill bacteria and algae and secondly, it acts as an oxidizer to remove dead material from the water. During the oxidation process, the hypochlorous acid reverts back to water and salt(Cl-). The above reaction will raise the pH in the pool, as liquid chlorine has a pH of about 13 ppm. It is there fore important to keep an eye on the pH which should stay between 7.2 and 7.8 ppm.
The short form: The cell of the Salt Chlorinator splits the salt into sodium and chlorine gas which sanitizes the water as it flows through the system to your pool. It the reunites into salt ready to be split again. In essence you have your own chlorine factory for your pool keeping your water safe and bacteria free.
What are the benefits of Salt Chlorinators?
One hears a lot about how the initial cost of the Salt Generator and the cost of the replacement salt cells negate the actual savings of these systems. From almost 10 years of experience with salt pools and various brands of Salt Generators, Aquajoy Spa And Pool has seen most of their customers recoup the cost of the units and cells in chemical costs.