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Using a naturally occurring plant to clarify water

The use of a natural, plant-based inhibitor of biofilm may be a useful complement to common pool and spa sanitizing products.

By Samantha Luedke

Since the beginning of time, Sphagnum moss has been conditioning and clarifying various bodies of water (e.g. lakes, rivers and ponds) around the world where moss bogs exist. However, the idea to harness this natural process and test its capabilities in pool and spa water did not transpire until two seemingly unrelated events occurred.

Ten years ago, while flying home from a recent business trip, Dr. David R. Knighton, co-founder of Creative Water Solutions (CWS), a developer of natural water conditioning products in Plymouth, Minn., read a magazine article about the military’s use of Sphagnum moss to pack soldiers’ wounds during the pre-penicillin days of World War I. According to the story, soldiers whose wounds were packed with moss rather than cotton survived in larger numbers, leading Knighton to believe the moss had anti-microbial properties.

Sphagnum moss from New Zealand in its natural state before its leaves are hand-harvested, sterilized and compressed for all-natural water treatment in pools and spas.

After discussing this hypothesis with his research and business partner Vance D. Fiegel, a cell and microbiologist and co-founder of CWS, they obtained some moss from the bogs of northern Minnesota to perform preliminary tests.

Shortly thereafter, while on a plane over northern Minnesota, Knighton noticed the lakes in the northern half of the state appeared clearer than the southern lakes. After further research, he discovered the northern waters were often flanked by moss bogs. This realization led to another hypothesis Knighton tested on his swim spa, which was experiencing water quality issues. He took some Sphagnum moss, put it in a perforated plastic bag and placed it in his spa. Within a few days, the water started to clear and the foul smell diminished. This prompted further studies into the ability of sphagnum moss to clarify pool and spa water.

Finding the right moss for the job

Fiegel and Knighton’s initial research looked at the proliferation of bacteria in idealized liquid cultures with and without Sphagnum moss. It examined the effect of a number of species of Sphagnum moss on the proliferation of several types of bacteria, as well as algae, fungus and mould. The results demonstrated that certain species of moss were effective at inhibiting the growth of these micro-organisms without killing them.1 If the moss was removed, the bacteria would continue to grow.

The role of biofilm

Whenever bacteria and water are combined, the bacteria always migrate to the surface initiating the formation of biofilm. The first bacteria that adhere to the surface produce and secrete a sticky matrix of complex sugar molecules called exopolysaccarides, which then incorporate proteins, nucleic acids and other compounds from the immediate environment.

In swimming pool and spa water, this biofilm matrix absorbs chlorine (Cl), bromine (Br) and other reactive ions into the sticky molecular matrix that covers the living bacteria. The ions may kill the bacteria closest to the surface, however, billions remain unharmed in the depths of the biofilm. These bacteria also quickly divide to replace the ones killed by the chemicals.

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