Specialty Products Inorganic
There are two major kinds of contaminants in pool and spa water- "Organic and Inorganic".
Organic contaminants in a pool or spa are things like bacteria, algae and bather waste, which are objectionable because they can affect the health of swimmers and bathers. Organic contaminants are controlled by such things as chlorine, bromine, ozone, ionizers, ultra violet sterilizers, algaecides and non-chlorine shock treatments chemicals.
Discoloration and sometimes cloudiness in a spa are caused by minerals coming out of solution, called precipitation.. If the precipitated metals have a color are smoother and are deposited on the pool walls, this is called staining. Staining and or colored water is caused by heavy metals like copper, iron, manganese. Quite often when you first fill a spa for example the water is colored green, from the copper in the source water pipes (not as common in well water sources). This is the same thing that causes a bath tub to get green stains in the household bath tub. You will notice that this green in your bath tub occur quicker when you bath with soap and or bath salts as they raise the pH of the water causing the copper minerals to come out of solution depositing on the bath tub surface. If chlorine was present in any quantity then the copper ions would form copper oxide and become a grey black color.
All these minerals come from the source water or from the pool or spa equipment itself if the water is out of balance. The minerals when in water form oxides, hydroxides, carbonates, sulfates, silicates and phosphates. Depending on the chemicals you are using in your water treatment program, you may be adding some more of them each time you treat the water, as with copper or silver algaecides, ionizers electrodes, chlorine generators electrodes or evens forms of chlorine like calcium hypochlorite. High levels of iron will cause brown stains to from in the spa
Using a sequestering agent will suspend the minerals and usually stop the staining and I some cases reverse the staining
The precipitated minerals in the water form hard crusty deposits on the heater and sometimes on the walls , this is called scaling or scale. Scale and or cloudy water is often formed from incorrect water balance and or high calcium or magnesium levels in the water. When calcium hypochlorite chlorine is used for sanitizing or shocking spa water, the calcium in this chemical often clouds the water temporarily as the calcium dissolves into solution.
Using a inhibitor will usually stop this scale formation