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Swimming pools and spas are introduced to various contaminants. Some of these contaminants cause problems in a swimming pool. Four types of goo have been characterised by research performed by Technology & Development. These are vinyl plasticiser goo, algaecide-humate goo, chlorinator goo, and pool scum.


Vinyl Plasticisers

Vinyl manufacturers use various plasticisers in the formulation of vinyl for swimming pools. These plasticisers act to keep the vinyl flexible and stable in a swimming pool. Sometimes, over the winter, unknown factors will cause an accumulation of this plasticiser on the surface of a vinyl liner. This accumulation of plasticiser appears as a "sticky liner" which, if touched, can cause sticky feet and hands and even leave "footprints" on the vinyl liner itself. Usually this material is relatively colourless and will not be evident until touched or brushed. When the vinyl is brushed, the brush will pick up dirt and other contaminants along with the plasticisers. This acts to colour the material a light yellow to darker brown colour which accumulates on the brush. This is a nuisance but also a natural occurrence that does not reflect a lack of quality or integrity of the liner. Vinyl plasticiser problems usually occur only the first or second season after opening a pool with a new liner. Fortunately, treatment of the problem is simple. Over a period of one to two weeks, as the water heats up, normal circulation of balanced pool water will alleviate the problem. Brushing is not necessary or desirable since it will only act to foul the cleaning brushes.



Quat-humate is an interaction of quats (quaternary ammonium complexes present in most algaecide products) with a class of substances called humates. Humates result from the decomposition of organic matter in leaves, grasses and soils. This matter can accumulate on the top of a cover or may just leach through a mesh cover. Usually this humate material, if present, will combine with the first application of an algaecide, such as Back-Up, and form a dark brown to black goo ring around the pool. Sometimes the goo will extend below the waterline, but most of the accumulation is at the waterline. The problem can be minimised by not allowing any portion of the water on top of the cover to enter the pool during the opening. Usually this water contains humates, in addition to other materials which can generate an initial chlorine demand or create stains later. Although this problem is typically an appearance nuisance, it is actually a desirable occurrence, as the Back-Up is acting to remove these unwanted organics, which may cause further problems later, from the water. Removal of the quat-humate substance is accomplished by brushing with BioGuard Surface Cleaner which can help dissolve this oily substance allowing the filtration system to remove it.


Chlorinator Goo

A third type of material can accumulate in automatic chlorinators. Most pools contain small amounts of oils and greases which can include natural body oils and suntan lotions. Suntan lotions can contain various carboxylates (a class of compounds) such as stearates and other organics. Carboxylates are the same materials which some manufacturers use to help bind chlorine tablets and sticks. Bio-Lab chlorine products contain no binders or stearates and therefore do not contribute to this "organic load." These organics can build up in swimming pools and eventually enter the chlorinator. Normally, the flow through the chlorinator does not allow the accumulation of these organics in the chlorinator but in periods when the system is not in operation, the organics present in the chlorinator are exposed to high concentrations of chlorine and low pH. These factors act to oxidise these organics into a yellow or beige, slightly sticky material. As the level of water rises and falls in the chlorinator, this material is deposited on the walls of the chlorinator unit. The oxidised material also can sink to the bottom and clog piping. This process of deposition is slow and usually occurs over a period of months or years. People may open the chlorinator, see this accumulation, and blame Bio-Lab chlorine tablets or sticks for this goo, when, in fact, most of the problem is contributed by bather load and the introduction of foreign organics to the pool.


This problem can also occur even though there is no apparent bather load because this is a slowly accumulating material. Any bather load in the past can contribute to a present problem. The key to this problem is prevention. Regular shocking of the pool with Burn Out oxidises some organics before they enter the filter and chlorination system. Enforcement of pre-swim showers helps wash tanning and other lotions from the body before entering the pool. Since most of the oils present in the pool are on the surface of the water, a tennis ball, large piece of Styrofoam or a "scum ball" placed in the skimmer will help catch the oils before they enter the chlorinator and cause problems. The absorbent material can be washed or thrown away after use. Presently, no safe chemical cleaning procedure has been devised for correction of the problem after it has occurred. Physical scraping of the material out of the chlorinator may help but if the cause is not corrected, the problem will recur.


Pool Scum

The fourth type of goo material in the swimming pool cannot be characterised in any particular group. Since a swimming pool is an open body of water, it is subject to contamination from the air, trees, pollution and even intentional vandalism. Many different environmental factors can contribute to a pool ring or scum. In most cases, these problems can be minimized by proper water balancing, regular super chlorination, and enforcement of shower rules. As was stated before, absorbent materials placed in the skimmer can also act to catch foreign organics and oils before they cause a problem. Since some scum lines are oily in nature, the alkaline BioGuard Surface Cleaner should be used to help remove these accumulations. Off The Wall® Surface Cleaner has also been shown to be effective in removing many of these unsightly rings and scum.


A summary chart follows detailing the problem, causes, and cures for the pool goo problems.



The above information is supplied by Bio-Lab and represents its best interpretation of available technical information at the time of preparation. The sole purpose is to supply factual information to Bio-Lab customers. It is not to be taken out of context nor used as support for any other claim not made herein.