Hot Tubs Engineered for the World’s Harshest Climates

Arctic Spas Manuals


99. Definitions of Terms

1.8 Definitions of Terms


Onzen™ An all-natural, salt-water softening and maintenance system.
Onzen™ Output Electrode

Three plate platinum-iridium Titanium electrode – equipped salt cell converts the saltwater
solution to sanitizer, and as this solution reverts back to its natural form (salt) after sanitizing.
Unless large volumes of water are added to the spa you never have to add more salt. The Three plate
electrode plastic outer casing is black in color.


Note: When the Onzen System has activated the Output Electrode to generate

sanitizer, the electrode gives off smoke effect.

Onzen™ Output Electrode


Modification status of the electrode fitted to the spa.
Calcium Hardness (CH)

Calcium Hardness is a measure of the total amount of dissolved calcium salts in the water.
CH helps determine how scaling or corrosive the water is. It is believed that calcium helps control the
corrosive nature of water. Calcium has two major problems in Hot Water Chemistry:


1. CH has a tendency to precipitate (fall out of suspension in high temperatures, where pH is above

2. High pH will cause calcium to precipitate. The problem with calcium falling out of suspension is that
it collects on the heater and pump, and shortens their life. High pH also reduces the life of the Onzen
Output Electrode.

Any natural corrosiveness in the water can be combated by maintaining a slightly

higher Total Alkalinity Level.


Total Alkalinity (TA)

A measure of how stable the pH is (a measure of the total levels of carbonates,
bicarbonates, hydroxides, and other alkaline substances in the water). TA is referred to as the water’s
“”pH buffer””. In other words, it’s a measure of the ability of the water to resist changes in pH level.
If the TA is too low, the pH level will fluctuate widely from high to low. Fluctuations in pH can cause
corrosion or scaling of the spa components. Low TA can be corrected by adding Arctic Pure, Perfect
Balance to the spa water. If the Total Alkalinity is too high, the water will be more susceptible to
scale and high pH. High pH may be difficult to bring down.


Note: Salt systems naturally drive pH levels to increase.

High TA can be lowered by adding Arctic Pure Salt Water Balance to the spa water.

Once the TA is Balanced, it normally remains stable, although some sanitizers, and the addition of more
water with a high or low alkalinity will raise or lower the TA reading of the water.

Potential Hydrogen (pH)

The pH level is the measure of alkalinity.

pH is measured between 0 and 14 denoting various degrees of acidity or alkalinity. Neutral water has a
pH of 7.0 Water below 7.0 is acidic and becomes more acidic as it approaches zero.

Water above 7.0 is alkaline and alkalinity increases as it approaches 14.

When the pH of water is 7.0 or below, chlorine will act primarily as a sanitizer. At this level, it is
very effective at killing bacteria. At 7.4, chlorine will act equally as a sanitizer and oxidizer. Above
7.8, chlorine will act principally as an oxidizer. The pH of chlorine is 11.7ppm. Spa water is
considered balanced if the pH level is within the target range, between 7.2pH to 7.6pH. Adding chlorine
either automatically through a salt system or manually, into spa water with high pH, above 7.6pH, will
further increase the pH level and dramatically reduce the effectiveness of the chlorine as a sanitizer.
This must be avoided by first reducing the pH level into the target range 7.2pH – 7.6pH. The chart below
reflects the loss of sanitizer effectiveness/sanitizer effectiveness based on the spas water pH level:




Maintaining a Balanced pH level between 7.2pH and 7.6pH is extremely important for:

• Optimizing the effectiveness of the sanitizer.

• Maintaining water that is comfortable for the user.

• Preventing equipment deterioration.

• Note: Salt systems naturally drive pH levels to increase, strive to achieve a balanced pH level.

If the spa water’s pH level is too low, the following may result:

• The sanitizer will dissipate rapidly.

• The water may become irritation to spa users.

• The spa’s equipment may corrode reducing life expectancy.

Low pH can be raised by adding Arctic Pure, Adjust Up to the spa water.

If the pH level is too high, the following may result:

• The sanitizer is less effective.

• Scale will form on the spa shell surface and the equipment.

• High pH will cause calcium to precipitate (fall out of suspension).

• The water may become cloudy.

High pH can be lowered by adding Arctic Pure, Salt Water Balance to the spa water.

It is important to check the pH on a regular basis. The pH will be affected by the bather load, the
addition of new water, the addition of various chemicals, and the type of sanitizer used.


pH Level

Sanitizer (Chlorine)

Loss of Effectiveness

based on pH Level

Sanitizer (Chlorine)


based on pH Level

6.0 4% 96%
6.5 10% 90%
7.0 27% 73%
7.2 38% 62%
7.5 50% 50%
8.0 78% 21%
8.5 90% 10%




Free Chlorine (FCL)

FCL is the active form of chlorine that actually kills bacteria and algae (It is a


Sanitizer is extremely important for killing algae, bacteria and viruses, and preventing unwanted
organisms for growing in the spa. At the same time, you don’t want too high a sanitizer level, or it can
irritate your skin, lungs and eyes.

Always maintain the sanitizer level in your spa within the recommended range.

Also refer ORP

Chlorine Residual The actual level of chlorine in the water after the chlorine demand has been satisfied.

Chemical used to kill bacteria.

Generic names: Chlorine, Bromine and Biguanide.

Arctic Pure, Boost

Adding Arctic Pure BOOST should be avoided unless the CI level is very low.

Parts Per Million (ppm) ppm: parts per million, a standard measure of chemical or mineral concentration.
Organic waste Debris such as microorganisms, perspiration, urine, etc. which needs to be burned up or
“oxidized” regularly to prevent haze, algae, chloramines, etc.
Shock An oxidizer that “burns off” the organic wastes which cause cloudiness and algae. It is a
generic term for a chemical used to oxidize organic wastes. Arctic Pure, Boost.