The chemicals used in spas or hot tubs are very similar to swimming pools. There are some differences. These differences are due to the higher temperatures that spas and hot tubs operate at, the very high bather load per unit of water and the small volume of water present.

Spas can go wrong much more quickly than swimming pools, if you leave your spa without any sanitiser in it for several days it will start o grow organisms in it very quickly. These organisms will not only be in the parts of the spa you can see but also in all the pipework. They will form a layer on the inside of the pipes known as biofilm. Biofilm allows all sorts of organisms to grow under its' protective layer. Once biofilm is established it is hard to get rid of it. The best thing then is to establish a routine so that it does not get established in the first place.

A typical routine for maintenance of your spa is outlined below:

Recommended Hot Tub Care Maintenance Routine

Daily :
Check sanitiser level & dose as required
Check pH level & dose as required
Weekly :
Oxidise hot tub with Shock
Check if your water is really clear and add Sparkle flocculant if necessary.
If there is foaming add Antifoam.
Two weekly :
Clean filter cartridge using Filter Cleaner
Take water sample to check water balance
If in area of high calcium hardness add Scale Remover to prevent scale deposits
Periodically :
Not all the pollution added by bathers to the spa is removed by even the best filters or chemicals.
At least once a month the spa will need completely draining & refilling. If the spa has been very heavily used it should be drained more frequently.
There are no hard and fast rules as to when this should be done but the following formulation seems to work well in practise:
Tub litres divided by daily bathers divided by 12 = days between draining & refilling
Example : 1200 litres divided by 2 divided by 12 = 50 days.
This is a good opportunity to give the spa a good clean. Shock the spa, circulate for at least an hour, clean all surfaces, drain, rinse and refill.