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STAINING AND SCALING

All water contains some levels of minerals and metals. When the minerals or metals are

dissolved and in suspension they are not visible. If they precipitate, or fall out of suspension,

staining or scaling can result. Metals such as copper, iron or manganese in sufficient

quantities can all cause staining. Prior to treatment you must first determine the cause. Algaes

or bacteria can cause green, black, yellow, brown or pink discoloration. These organic

deposits can generally be distinguished from mineral or metal staining by their response to

chemical treatments (sanitizer and algaecide) and in most cases can be removed with a

vigorous brushing (although they may grow back). See Algae for more information. Leaves,

worms and other organic material left in the pool can also cause staining. This type of staining

will usually respond to a sanitizer and a follow up stain remover.

Ruling out the above, one can assume that the discoloration, throughout the water or in

deposits, is caused by metals or minerals that have oxidized or dissolved and have

precipitated (come out of solution). Unbalanced pH, Alkalinity and the addition of sanitizers

are all possible causes for such precipitation. High levels of metallic salts such as calcium or

magnesium in suspension may cause cloudy water, when they form hard white deposits or

crystals on the pool surface it is referred to as scaling. Heavy metals like copper and iron will

cause discoloration or when deposited, staining. Green usually indicates copper or iron, red

and brown –iron, black or brown -manganese.

As with all water problems, prevention is preferred to treatment. The best way to prevent

staining is to have your pool water tested at our store PRIOR to the addition of ANY

pool chemicals. Often the original source water that you use to fill your pool may contain iron

or other metals or minerals that are not visible to the naked eye. If a test reveals the presence

of metals or minerals in your water our pool professionals can recommend a treatment method,

often consisting of the addition of a sequestering or chelating agent. These chemicals are used

to help bind the metals together so they will not precipitate. Some pool water will require regular

additions of these chemicals, especially after the addition of make-up water. Have your water

professionally tested for metal content at the beginning of every season. Another key in

preventing precipitation is to follow the chemical guidelines for adjusting pH and alkalinity,

high, rapid fluctuations can cause precipitation. Corrosion of metal equipment components

due to unbalanced pH and Alkalinity can also cause dissolved metals to precipitate in the

water. If staining or scaling does occur our pool professionals will recommend a stain and scale

remover for treatment. Follow the steps below to help prevent staining and scaling:

Have your water professionally tested for metals.

DO NOT ADD ANY CHEMICALS UNTIL THIS TEST IS PERFORMED*

Follow water balance guidelines for pH, Total Alkalinity, TDS and Calcium Hardness. Add

pH and Total Alkalinity adjusters following the application directions closely.

DO NOT add

too much chemical or make too rapid of an adjustment in a short period of time or

precipitation can result.

Routine maintenance doses of a sequestering or chelating agent will help prevent staining

and scaling- Strongly recommended in plaster and fiberglass pool finishes..

Poor filtration or circulation will accelerate metal precipitation.

Pool owners with plaster and fiberglass pool surfaces need to be especially diligent in stain

and scale prevention, although all pool types are susceptible- the penetrable surface of

plaster pools make them more vulnerable to staining and scaling.