Typical pool staining results from microorganism growth, precipitation of oxidized metallic compounds
or organic contaminants. CGT vinyl liners are formulated to have anti-bacterial/anti-fungal properties
to resist foreign microbial growth and contain a protective top coal to preserve the printed patterns.
The most common types of staining seen are:
Black Algae Staining
These are small block spots on the pool surface from chlorine resistant organisms that require physical
contact ‘with a nylon brush) in addition to chlorine to remove. Further steps in addition to the physical
removal are to: reduce pH to lower limit 17.2), superchlorinate the water 110.0 ppm), and odd a dose
a4 a quaternary type algaecide. These con all aid in removal of the black spots.
Black and Pink Staining
These pink or grey blotches which can be seen on the liner are the result of the metabolic process
of microorganisms. A dye is excreted that is highly soluble in plasticizers used in flexible INC and
has the potential to migrate through the entire thickness of the liner from its origin on the bock side.
This staining can be seen on both sides of the liner and generally requires liner replacement
and chlorination of the contaminated surfaces to correct.
Copper, Iron and Manganese will form oxides in chlorinated pool water and can deposit on the pool
surface. These stains are generally black, brown or grey in colour. The metals may be introduced into
the pool via the water source used to fill the pool.
Pool Goo and Organic Contaminants
The consensus in the pool industry is that there are several sources of sticky substances, often referred to as “pool goo” or “pool tar” that adhere and coat portions of the pool surface.
Source of Issue:
- Compounds formed from the interaction of ammonium compounds in some algaecides and decaying organic material such as leaves grasses insects etc.
- Interaction of algaecides with other substances. Even chlorine can interact with algaecide and form sticky material in both chlorine and algaecide exceed the recommended dosage levels.
- Chlorine goo can form when organic material from cosmetics, tanning lotions etc are oxidized by high chlorine concentrations resulting in a beige waxy material.
- A light coating a vinyl plasticizer may exude to the surface of newly-installed liners during the first idle period of winterization. This material is clear and only turns dark if contaminated with dirt. The occurrence of pool goo is only known to occur with the first winterization of the liner.
- Pool scum is a ring that forms around the pool at the waterline and is made of soil contaminants from suntan lotion, environmental pollution and organic materials from bather load etc.
Potential Ways for Eliminating Pool Goo
- Reduce and maintain pH at 7.0 – 7.2.
- Super chlorinate to 6.0 – 8.0 ppm and let equilibrate to free chlorine concentration of 1.0 – 3.0 ppm.
- Slop using algaecides.
- Use heater to speed up warming of water (if available).
- Continue to circulate water and monitor pressure of filter.
- Backwash filter as often as required.