Spa Care Program

The requirements for caring for your spa are very much the same as for a large pool.

The major points of difference are :

A spa has a much smaller volume of water
It is typically heated to a much higher temperature
The bather loadings are usually much higher than a pool (in relation to water volume)

This means that :

Water sanitation is even more important
Maintaining water clarity is a major issue


Spa pools require correctly balanced water to maximize bather comfort, maximize sanitizer efficiency, and prolong spa surface and equipment life.

Balancing means monitoring the levels of pH, alkalinity and hardness in your spa water.

Typical ideal levels for the most common acrylic type spas are :

pH   7.2-7.6
alkalinity   80-150
hardness   180-250

You need to adjust pH to the desired levels by adding spagard pH Increase (to raise pH) or spagard pH Decrease (to lower pH)

You need to add spagard Alkalinity Increase to raise alkalinity. Alkalinity can be lowered by adding spagard pH decrease (but note this also has the effect of reducing alkalinity)

You can raise hardness by adding spagard Hardness Increase. It is not possible to lower hardness in a practical manner. This can be done through water dilution - removing spa water and replacing with fresh tap water. Although this may upset the other balance parameters which may need to be adjusted.


Spa pools require regular sanitizing to maintain good quality water for bathing. The sanitizer takes on the role of killing bacteria, viruses and algae. The addition of an oxidizer is also essential to burn out organic contaminants that build up over time to cause spa water to go cloudy.

Chlorine is an effective sanitizer and oxidizer and is a common form of sanitizer for spas. However, it is not very stable at high temperatures, causing it to dissipate quickly in a spa environment.

Bromine is perhaps a better sanitizer for spas because it is more stable at high temperatures. Typically, bromine has a small portion of chlorine content as pure bromine is not a good oxidizer whereas chlorine is.

Approximately 5% of bathers have a reaction to bromine. Approximately 17% of bathers have a reaction to chlorine. For this reason, poynters poolside is a specialist in alternative sanitizers.

Ozone is now widely used for spa sanitation. Ozone is much more effective than either chlorine or bromine at sanitizing when sufficient ozone is introduced into the water. It is also an oxidizer. Because ozone is simply O3 (oxygen + an extra molecule) it is an environmentally friendly sanitizer. The extra molecule is very unstable and readily attaches to foreign matter to kill and oxidize away. The major limitation with ozone is that because it is so unstable, it doesn't remain in the water for long. This means spa water has no residual of sanitizer. Spas run on ozone should ideally be run 24 hours a day if they are not assisted with a chemical sanitizer. If this is not the case, the spa water must be supplemented with a small amount of either chlorine or bromine.

poynters poolside also supplies SpaRX, a mineral system comprising a patented blend of copper, zinc and silver which either reduces chlorine by as much as 75%, or can be used as a 100% chlorine free system when used as part of a 3 step system.

Water Replacement

Because of the high bather loads and small volume of water in a spa, the build up of chemicals and organic matter in a spa can build up quickly over time. This build-up is known as TDS (total dissolved solids). It comprises anything dissolved into the spa water - chemical residues, bather contamination etc... High levels of TDS lead to sanitizer ineffectiveness and a gradual clouding of spa water that will not disappear.

Spa water should be replaced every 1 month - 2 months. With ozonated water, it may be possible to change spa water every 3 months. The frequency of the water change is influenced by the number of bathers using the spa. Use your judgement.

If you are using Dichlor (soluble chlorine) , you should change the water in the spa every month to avoid a build up of chlorine stabilizer in the pool water.

Filtration and Circulation

Just like swimming pools, spa pools need to be filtered regularly. The action of filtration in a spa pool serves to circulate water in the spa and to cleanse the water through the filter.
Circulation is important for several reasons:

  • water movement reduces the potential for algae growth
  • water movement disperses and mixes chemicals in the spa
  • water movement is necessary to run the heater
  • water movement creates the spa hydrotherapy

By having the filter running, debris and contaminants are caught in the filter. Typically the a spa will have a cartridge filter that will periodically (recommended fortnightly) need to be cleaned. Some in-ground spas may have a sand filter which will need to be backwashed on a regular basis (recommended at least once a month).
Cartridge filters should be periodically removed and soaked overnight in spagard cartridge cleaner to remove the build up of body fats which will eventually clog the filter.


Brush down the walls of the spa at least weekly to dislodge dirt and any algae build-up. Remove any leaves or other debris from the spa at least weekly to reduce the potential for algae and viruses to breed.


As with swimming pools, testing of spa water on a regular basis is essential. We recommend spa water is always tested prior to use for correct sanitizer level and pH. Test strips are convenient for this purpose. The 3-in-1 test strips will test chlorine (or bromine), pH and Alkalinity levels. Chlorine levels can change quickly. pH will change less dramatically - the rate depending on the type of chlorine used and the amount of alkalinity in the pool. Alkalinity, at the correct level in the pool, will change slowly over time. If you are changing your spa water every month, it is probably sufficient to just check the sanitizer level and pH on an ongoing basis, once the initial start-up water balance has been done. (see below)

Typical Start-up for Auckland Water

Here are our typical start up procedures for fresh water from the Auckland water supply. (For people outside of Auckland, these procedures may not apply as your water balance may be different)

Fresh Water

Each time the spa is refilled, carry out the following treatment to achieve correct water balance. The following directions are applicable for a Spa Pools of approx 1300-1500L (a six person medium size spa). Adjust quantities to suit your spa.

  • Pre-dissolve 200g spagard Alkalinity Increase in a bucket of water. Add to the spa and run the filter for half an hour to mix adequately.
  • Check pH and if it is above 7.6 add 20g (about 2 dessertspoons) spagard pH Decrease. Pre-dissolve in a bucket of water. Add to the spa and run filter for one hour and recheck pH. Add a further 20g Spagard pH Decrease if pH is still above 7.6.
  •  Pre-dissolve 200g spagard Hardness Increase in a bucket of water. Add to the spa and run filter for half an hour.

Daily Treatment

Whenever the spa is used, add 5-10g (1-2 teaspoons) spagard Dichlor directly to the spa one or two hours before use and again immediately after use (quantity will depend on chlorine demand). There is no need to pre-dissolve, just sprinkle over the water surface.

Weekly Treatment

  • Pre-dissolve 20g spagard Shock! in a bucket of water and allow to stand for half an hour to enable insoluble residue to settle (before adding only the clear liquid to the spa). When shock dosing always ensure pH is 7.6 or lower before adding Shock!  (to avoid cloudiness). Remove the spa cover, add Shock!, filter for half an hour, operate supercharger (aerator) for five minutes, and then replace cover. Shock dosing is essential for the removal of body fats and the killing of bacteria and algae.
  • Add 20ml spagard Water Clarifier directly to the spa and run the filter for half an hour. Repeat after heavy usage or if spa water loses clarity.
  • Clean cartridge filters. Dissolve 500g spagard Cartridge Cleaner per 20L of water and soak overnight in a bucket. The following day, wash down with warm water.


  • Do not shock dose when adding water balance chemicals or when pH is above 7.6
  • Do not drain spa completely if it is set in the ground as in-ground water pressure may lift it out of the ground. Empty only to the seat level.
  • Do not use soap or detergents.

Water balance chemicals can be used 12 hours after shock-dosing.
Spas should be filtered for a minimum of one hour daily, or longer with regular usage or high bather loads, typically over 4 hours or more per day.

Bromine usage for spas

Bromine residual must be maintained between 2-5 ppm (parts per million).
Add 3 x 20g tabs weekly or whenever residual drops below 2 ppm. 
Check bromine level regularly.
Add tabs directly to automatic feeder or to a dispenser placed near the return line.

spagard Shock N Soak! (a non-chlorine shock treatment) may be used in place of spagard Shock!