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Pool Chemistry - Natural Pools Australia

Pool chemistry and what it means

Ph and total alkalinity are one of the 2 main pool-balancing tests that most people struggle with.
Ph means the range of acid and alkaline.

The 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 water is basic; 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.

Whereas Total Alkalinity means; The total alkalinity (TA) is a measure of how much of the alkali substances are in the water. In the swimming pool water, we are concerned with bicarbonate alkalinity, which should be between 80 ppm and 120 ppm. It is a measure of water's resistance to change in pH - TA is the amount of alkali in the form of bicarbonates, carbonates and hydroxides present in the pool water. TA affects and controls the pH.

When balancing acid and alkaline it is always important to conduct the Total Alkalinity first before adjusting the Ph.

Alkaline material helps stabile Ph reading.

A low total alkalinity allows the pH to randomly fluctuate.

Many factors can cause fluctuations in ph and Alkalinity like tap water; bather load, rain and most commonly plaster pools.

Concrete plaster pools contain alkaline material in the plaster that leeches alkaline constantly into the pool water.

Pool balancing can be corrected but 4 / 5 days later the ph rises quiet quickly due to the plaster leeching alkaline. Generally these pools are supposed to cure after 12 months but it is noticed it continues years and years after. In these cases it is recommended to use an automated ph doser to help regulate the ph.

Ph results are required to be set at 7.5

Total Alkalinity results are required between 80ppm to 120ppm.

Quite often using an automated ph doser, we notice the Total Alkalinity eventually starts to reduce slowly over a 6 to 8 week period till it reaches a point it is below 70ppm. If this happens we need to turn the automated ph doser off for 24hours add the required amount of sodium bicarbonate to raise the Total Alkalinity up to 120ppm, then after 24 hours turn ph doser back on again and resume the automated dosing.

Good news is the SwimFresh System and ozone products are all PH neutral, except the Ozone Activator, which has a slightly mild acid base.

Our Natural Pools Australia SwimFresh Pools will not cause radical changes in Ph. Unlike Chlorine which has a very high PH of 12 -13 and always requires a lot of acid to counter act the high ph changes.
SwimFresh pool balancing is far easier to maintain, as it does not fluctuate the ph like chlorine does.

Another important test is Calcium Hardness.
The calcium hardness is a measure of the amount of lime dissolved in the water. Water with a CH of less than100ppm is described as soft water and draws lime out of the concrete of cast pools and tile grouting, leading to disintegration. It also makes the water aggressive. Water with a CH above 300ppm is described as hard water and causes lime to be precipitated. Lime precipitation causes lime-scale to form on the walls and pipes of the pool and in the equipment.

It is important to keep calcium Hardness at a min 150 to 300ppm.

This test only needs to be done 3 or 4 times a year, once calcium reading is corrected it will maintain its level and only reduces from dilution (heavy rain or topping up with the pool hose)

Pool Chemistry - Natural Pools Australia

Unbalanced Ph and Total Alkalinity pool problems
Neglected pool balancing can cause damage to pool surfaces, affect equipment, cause stinging eyes & burning sensation on skin. It also creates a “frozen environment “ where the sanitisers cannot work effectively thus resulting in cloudy water and allows algae to grow.

Any questions regarding Pool balancing the team at SwimFresh are always happy to advise you through the testing procedures and keep you on track for your perfectly balanced SwimFresh pool.

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