Salt water hot tubs have some misconceptions behind them.
- It is not the same as the ocean. The ocean has tens of thousands PPM of sodium. (notice I used sodium, not salt) Salt water hot tubs (and pools) start out with only 1500 to 2100 PPM of sodium. A fraction.
- All bromine and Chlorine start out as sodium. Bromine, started out as Sodium Bromide (NaBr). Chlorine (NaCl)......take a look at the box of table salt. Salt water hot tubs are nor corrosive then any other tub out there. Acidity actually come from other sources.
Okay, now that we understand what and where the chemistry comes from, lets look into how it works for our hot tubs.
- We cannot use NaCl in a hot tub, it is affected by temperatures over 98deg. (which is every hot tub out there). So, we have to use a bromine base, that is not affected by heat, NaBr. This is of course the raw material used to make an active bromine, which is what kills the bacteria. We add, based on the size of tub, many gallons (or Litres) to the tub to bring the PPM up to the appropriate level. (between 1500-2100 PPM). The NaBr, is mixed up with the water and is now ready to turn into Bromine.
- We turn the NaBr into Bromine by passing the water and NaBr over something called a "salt cell". This cell is made of graphite. (pools use titanium) As the water comes in contact with the surface area of the cell, the energy that is being passed through the cell releases the Bromine molecule and turns the sodium molecule dormant (but not gone). We now have an active, or FREE BROMINE. There is usually a dial that can adjust the strength of the cell, to give you more bromine.
- As the bromine comes in contact with bacteria, the bromine is then used up, and goes dormant bringing it back to its original state (NaBr). As your hot tub circulates, it simply recycles the inactive back to active, over and over again. And because Na is a mineral, it does not evaporate with your water, so there is far less draining of your tub, and considerably less chemicals....There is a major cost savings.
- If someone tells you that salt systems are not good for your tub, understand this. The reason for dumping a regular hot tub every 3 months or so, is because of the pucks and powders that you use in the tub, they are full of all sorts of fillers and the pucks are full of glues and binders that help make them dissolve slowly. This increases your ppm count, but more importantly it increases it with bad parts. FACT. Salt water hot tubs do not use pucks and powders(aside from the occasional blast after heavy use).... It is actually far better for your tub, they use only liquids. The liquids are much better for your tub, and dissolve much better then the pucks and powders.
