How to maintain your spa pool for best results

The amount of disinfectant required depends on how much your spa is used. As a rough guide, a small spa requires as much disinfectant as an average sized swimming pool. To ensure that the disinfectant is effective, the water must be sparkling clean and the chemistry must be right. Follow the step by step instructions below to achieve the best results. A 4 in 1 test kit is recommended for this purpose.

Step 1:
Estimate the volume of your spa or ask the supplier to help with your calculations. Most private spas have 1000-5000 litre capacity.

Step 2:
Check the pH - pH is a simple measure of acidity or alkalinity. The pH of spa water should always be above 7.0 (measured at room temperature, not warm) to avoid corrosion of the heater and filter. However, it should not be higher than 7.8 as this will reduce the disinfectant effiency, especially that of chlorine which is more effective at the lower end of the recommended pH range. To increase or decrease the pH simply raise or lower the total alkalinity following step 3.

Step 3:
Adjust the total alkalinity - ensure that the total alkalinity is in the range shown in table 1 below.

• To increase the total alkalinity by 10 mg/L add 17g of sodium bicarbonate for each 1000 L of spa water.

• To lower the total alkalinity by 10 mg/L add 20 mL of hydrochloric acid or 24g of dry acid (sodium hydrogen sulphate) for each 1000L of spa water.

When dosing the spa water with chemicals always OPERATE THE FILTER PUMP but DO NOT use the air blower or the venturi.

Step 4:
Disinfect the water - this is essential to kill all the harmful microorganisms. Chlorine as sodium hypochlorite, bromine as bromochlorodimethylhydantoin (BCDMH) tablets or a hypobromite-hypochlorite kit are suitable.

Note: Bromine is the prefered disinfectant in spas as the liquid chlorine - sodium hypochlorite - goes off with storage and dosing may need to be increased. Calcium hypochlorite (dry chlorine) is not recommended in spas as it causes scaling of the heater element.

Step 5:
Shock dose - after heavy use of the spa or on at least a weekly basis, shock dose the water at the levels shown in table 2 below. Our Shock Right tablets are ideal for this.

Table 1: Recommended spa pool water quality

* Maintain these levels at all times
** Minimum
*** At room temperature
**** Lithium hypochlorite is equally satisfactory

Table 2: Dosage rate of disinfectants

What to do

• Make sure your spa pool water is not hotter than 40º C. An ideal range is 35-37° C. Use a thermometer to check.

• Spa use should be restricted to 20 minutes at any given time at maximum temperatures to minimise heat stress.

• Extended exposure times can promote skin infections.

• A spa should not be used after heavy drinking, if you have been seriously ill, have had recent surgery, are pregnant or if you have a heart condition.

• Keep your head out of the water. Do not swallow spa water.

• Clean your spa filter regulary, according to the manufacturer's instructions or at least fortnightly. Use our spa bath cleaner for this job. High temperatures accelerate the release of body oils and greases into the water.

• Empty your spa and thoroughly clean:
  - at least every 3 months or up to fortnightly if it is heavily used;
  - if it scales up the walls, foams excessively or looks grimy; and
  - if dosing of disinfectant does not eliminate smells.

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