Water Balance

Balanced pool water is the key to a healthy pool

Pool water is said to be balanced when all the components are at their recommended levels.

TA, or total alkalinity is the most important indicator as it buffers pH, keeping it more stable. If TA is too low, pH will be erratic and “bounce”. If TA is in the correct range – 80 to 120ppm – pH will be stable.
pH is a measure of the acidity of the water. The pH scale goes from 0 to 14, where pH 7 is neutral. If the pH is above 7, the is alkaline; if it is below 7 the water is acid.

The optimum pH for pool water is 7.4, since this is the same as the pH in human eyes and mucous membranes. A pH of 7.4 also gives good chlorine disinfection.


“0.10ppm of chlorine is very effective in treating a pool when there are copper and silver ions present in the pool.” (University of Arizona)

By using the Mermaid Pool Purifier, 80-90% less chlorine is required than a pool that only uses chlorine for sanitation. The Mermaid system does require some chlorine to work optimally.

Therefore, measuring chlorine levels is not required – a floater set on its smallest setting is sufficient chlorine.

How to make my pool clear and not cloudy

Another reason that your pool water may not be clear and blue is poor filtration. You need the correct size pump and filter combination for your pool size as shown below:

  • 20 – 50 000 litre pool = 0.45KW pump with 2-bag filter
  • 50 – 85 000 litre pool = 0.75KW pump with 3-bag filter
  • 85 – 150 000 litre pool = 1.1KW pump with 4-bag filter

The filter sand traps dust, impurities, suntan lotion etc. Most of these impurities are removed during backwashing, but eventually the sand needs to be replaced, usually once a year.

How many litres of water are in your pool?

Use our calculator to calculate your pool volume, click here

By using the Mermaid Pool Purifier, 80-90% less chlorine is required than a pool that only uses chlorine for sanitation.


  • “Legionella pneumophila, which causes the lethal Legionaire’s Disease and which can be present in public waters, was killed approximately 100 times faster when 0.20ppm of copper and 0.02ppm of silver were added to 0.20ppm of chlorine as compared to the use of chlorine itself. Legionella is very resistant to even higher levels of chlorine.” (Professor Charles P. Gerba, Department of Microbiology, University of Arizona)


  • “Two different chemicals added together may allow more efficient disinfection kinetics to be achieved. One substance targets the surface of a micro-organism killing and injuring the cells while a second substance targets the nucleic acid of the micro-organism destroying the remaining injured micro-organisms. By using this method of dual disinfection, reduced levels of both substances may be more effective than much higher levels of either individual substance.” (G.R. Taylor, Surrey University)


  • “Copper and silver ions used in conjunction with lower levels of chlorine can provide control of total-coliform and heterotrophic bacteria that is equivalent to the control provided by chlorine at high levels. Ion concentrations are readily controlled in a narrow range around a set point and form a long-lived residual that protects against microbiological growth.” (Thomas J. White, Journal of Environmental Health)
  • “Silver is a bactericide whose properties have long been known. Copper kills algae. When used together they reduce chlorine needs by 90 percent.” (Jim Motavalli, Earth Action Network)


  • “Thanks to eye-opening research, silver is emerging as a wonder of modern medicine. An antibiotic kills perhaps a half dozen different disease organisms but silver kills some 650. Moreover, silver is virtually non-toxic. Dr. Harry Margraf of St. Louis, a pioneering silver researcher, says: ‘Silver is the best all around germ fighter we have.’ ” (“Our Mightiest Germ Fighter”; Science Digest)


  • “The value of silver in medicine, and as a purifier has been acknowledged for centuries. Egyptians implanted silver plates into skulls with surgery. In Ancient Greece and Rome, people used silver containers to keep liquids fresh. When settlers moved across the American West, they would purify a container of water by putting a silver dollar in it overnight. Towards the end of the 19th century, other medicinal uses for silver were developed including the use of silver and mercury in filling cavities, and the dropping of a silver filtrate solution into the eyes of newborn babies to prevent blindness due to infection.” (Dr. Harry Margraf, “The Story of Silver in Medicine”; Gold & Silver Newsletter)
  • “Scores of independent tests have shown that silver promptly kills bacteria in water and maintains water purity over long periods of time.” (“Tests Show Silver Best Water Purifier”; The Silver Institute Letter)


  • Both NASA and the Soviet space program use copper-silver systems to purify and recycle drinking water on their space missions. (“Winged-Ferry to Shuttle Between Earth and Space”; The Silver Institute Letter)


  • “The most dramatic purification tests occurred in 1976 in a 20,000 gallon swimming pool in Nebraska. There was no disinfectant of any kind in the water. Fifty gallons of municipal sewage waste water was put into the pool. That produced a dangerous concentration of 7,000 E.Coli cells per 100 millilitre [half a cup] of water. Contents of the pool were then pumped through a tank containing silver for disinfection. Within three hours the pool was entirely free of E.Coli and the water contained only 3.2 parts of silver per billion parts of water (0.0032ppm). (“Silver Guards Good Health:’; The Silver Institute Letter)
  • “The Allegheny County Health Department in Pennsylvania conducted tests in a 152,000 gallon pool which previously had been disinfected by a 50 pounds per day chlorinator. The system was replaced by a silver system for the swimming pool season. The County Health Department took up to 50 daily samples and found that silver ions remained in the pool at the low steady rate of 20 parts per billion (0.02ppm). The water remained free of bacteria throughout two seasons. In contrast, 65 water samples from 30 other pools having a concentration of 700 parts per billion (0.7ppm) of available chlorine showed a mean of 1.3 pseudomonas and 7.3 staph cells per millilitre of water.” (“Silver Carbon Filter Purifies Swimming Pool”; The Silver Institute Letter)


  • “Silver-copper systems are capable of inactivating enteric viruses such as the polio virus in the presence or absence of free chlorine, which should be useful in the control of these agents in swimming pools.” (Professor Charles P. Gerba, Department of Microbiology, University of Arizona)


  • “The silver-copper treatment has resulted in far healthier animals with healthier skin, and small scratches and abrasions that under chlorine did not heal well now heal more rapidly; most important, eye problems are markedly reduced.” (Judy Tuttle, Supervisor of the San Antonio Children’s Zoo)