: why does saltwater systems in pools kills bacteria and algae, while the sea is full of life?
In: 634
[deleted]
The salt in saltwater systems are passed through a electrolytic chlorine generator. This converts the salt to chlorine rather than relying on manufactured chlorine which is harsher.
The salt in saltwater systems is converted to chlorine (the Cl of NaCl which is salt), which in turn kills bacteria.
Because salt water pool systems convert the chlorine ion in salt (a sodium ion with a chlorine ion [NaCl]) into actual chlorine through electrolysis. The chlorine generated kills off bacteria and algae much like a regular pool. This system eliminates the need to dump chlorine into the pool as it is generated from the added salt.
some things aren’t designed to live in saltwater.
You as a human I’m assuming probably drink clean water and can’t effectively be hydrated by saltwater, if you just drank saltwater, you wouldn’t be hydrated properly because you’re not really designed to, the same kind of logic applies to different organisms. Some can effectively live in saltwater and others can’t. It all depends on how they adapted to their environment, some animals exist in both too.
Saltwater pools are chlorine pools, just instead of you getting chlorine concentrate (which is made from salt) you get salt and the machine makes the chlorine for you. The machine does some of the checking for you so it makes for less work and a smoother chemical profile. Costs a lot though
Salt water pool uses electrolysis to create chlorine that disinfects a pool just like any other pool you add chlorine to. The reaction is 2Clˉ(aq) + 2H2O(l) → Cl2(g) + H2(g) + 2OHˉ(aq). Chlorine gas is produced which dissolves in the water and is what creates hypochlorous acid which has the bleach like anti microbial action. Also produced is hydrogen gas which you see bubble out of the water, and OH- ion which is why the pH keeps going up in salt water pool and you need to add periodic acid to keep ph in mid to high 7. range.
At any given moment the saltwater swimming pool contains: salt (NaCl) water (H2O); sodium, chlorine, hydrogen, and oxygen ions formed from them; and the recombinant products formed from the ions, sodium hydroxide (NaOH) and Hydrochloric acid (HCl). These molecules form, break up and reform constantly. The Chlorine is one of the active germ-killing ingredients in the pool.
Problem is Chlorine, Hydrogen, Sodium and Oxygen ions also form gases e.g., Cl2, H2, O2, NO and NO2 that disperse to the atmosphere. Water also can evaporate as water vapour. So over time the pool loses its saltiness and germ killing qualities so more water and salt must be added periodically
The germs killed by chlorine in a pool cannot survive the relatively high concentration of salts in the water. However the sea is full of life that has developed with the even higher concentration of salts, acids and ions in the seawater. Most of the life in the sea would not survive in a saltwater pool.
Latest Answers