Interior Finish Stains

It is possible to remove or lighten stains in your pool.  Our recommendation is to perform tests to determine whether there are inorganic or organic stains or both.  This can be determined with the use of acid and chlorine.

Before testing, first be sure the water is perfectly balanced for total alkalinity, pH and calcium hardness.  Then, check for metals and, if present, add a stain and scale control prior to performing stain removal tests.  With the filtration system turned off, put one chlorine tablet on an area of the interior finish stain, then use a nylon sock with a cup of dry acid with a rubber band around it. Place that on the stain in a different area.  Please be aware that on vinyl, PVC membrane and some plaster finish pools chlorine may bleach or affect the finish.

The next day check to see if the stain was removed by one or the other.

If the chlorine removed the stain:  With the pool perfectly balanced, shock the pool according to label directions.  If that removes the staining or lightens the staining then you may perform the shock treatment repeatedly until the stain is removed.

If the acid removed the stain:  With the pool water balanced otherwise, lower the pH to 6.0 – 6.5 for a period of three days and brush with a stainless steel brush (for plaster finish pools) or a nylon brush (for vinyl and fiberglass pools) three times per day until the stains are removed.  Be sure to turn off the filter system during this time.  Place a circulation pump in the pool. After the treatment, raise the pH and resume running the system.

A high pH also will cause staining that can be impossible to remove.

Metals in water such as iron will react with chlorine causing staining.  Adding a sequestering agent such as stain and scale control can remove or lighten stains caused by metals (recommended to use as a regular regimen).

UltraViolet Ozone and Staining:

Add a HydraPure™ Ultraviolet Ozone (UVO). The Advanced Oxidation Process (AOP) to eliminate staining from metals.  UVO is so powerful it can oxidize non-organic materials such as dissolved metals (iron, copper, manganese, etc.) eliminating common metals staining on the pool surface.

Equipped with a AquaRite salt water generation system chlorine expense will be reduced to zero and keep everyone swimming safely.  UVO eliminates 99.9% of pathogens including the ones that chlorine does not kill.  This means much safer water that is much easier to maintain and the pool surfaces are less susceptible to all types of staining!  

HydraPure (HYD) UltraViolet Ozone System: $3,895.00 installed

AquaRite (AQR) Salt Chlorine Generation System:
AQR S25 (up to 25,000 gallons): $2,995.00 installed
AQR S40 (up to 40,000 gallons): $3,195.00 installed

Save $200.00 With Purchase Of Both Systems!
Package Installed Price:
AQR S25 and HydraPure HYD UVO3 $6,895.00
AQR S40 and HydraPure HYD UVO3 $7,090.00

Sometimes stains are caused by bacteria underneath the lining of the pool.  In that case, it may not be removed from the surface as the bacteria has impregnated through the liner from the earth.  The lining may need to be removed, discarded, the bacteria treated to be eliminated then the lining replaced.

Do not allow anyone in the pool during these tests or treatments.  Be sure the pool is perfectly balanced before allowing swimmers to enter the pool.

Always add the chemical to water, never add water to the chemical.