Indication of Metals After Shock Chlorination
Have you ever cleaned your swimming pool of stains and spots at the beginning of the season and while you have done the proper maintenance on all the mechanical equipment you fill the pool with fresh water and after perchlorination (shocking) the water turns green or coffee? The coloring of the water, you will have noticed, that by continuing the recirculation in the following days it recedes. This water shock reaction is not algae but a high concentration of metals. This is a very common problem encountered in pools that are filled with borehole water. Wells usually because they have not undergone any chemical treatment are very likely to have a high concentration of metals, hardness (salts), micro-organisms and bacteria. In addition to the color of the water another indication of a high concentration of metals can be stains on metal parts of the pool, which have corroded. This problem is not a danger for bathers, but it is very possible to see a change in color on bathing suits or light colored hair of bathers. So the first thing we must do if we have established any of the above is to do either a physicochemical analysis of the water in a certified chemical laboratory or to check their concentration with a photometer or metal measurement kit. Remember the statue of liberty which is made of copper. What color has it become…green…Green color is an indication of presence of copper while brown is presence of iron. Besides copper and iron there are other metals that we can meet but not so often. These are manganese, lead, nickel, etc. When metals come into contact with an oxidizing agent such as chlorine or oxygen they oxidize and change color. Below are some examples of metal oxidation and color change.
Presence of copper in water Presence of iron in water
After establishing their presence, either by using a test kit or photometer or by physicochemical analysis in a certified chemical laboratory, we can use specialized chemicals to remove them. If stains have been created on the surfaces then at the first filling and before we perchlorate the pool, where the free chlorine has a zero concentration, we apply the specialized chemical locally Multi Stain Remover. The settled metals dissolve again in the water and are thus removed from the surfaces. If it is very persistent and old, the stain may need a second application. In this way we remove them from the surfaces but not from the water. These metals from the stains dissolve back into the water and are very likely to redeposit on the surfaces and re-create unwanted stains. To remove the dissolved metals in the water, which have come from either a stain we removed or are in the source of the water, we use the specialized chemical No More Metal, which binds them and leads them to the filter. We should not forget, when the source of the water contains metals, that we should add No More Metal every time we add fresh water into the pool, so that the metals are bound and do not create problems either in the pool or in the hair and in bathing suits.
