Active Oxygen - Frequently Asked Questions

What is Active Oxygen?

Active Oxygen sanitation is based on the use of potassium monopersulphate tablets.  Potassium monopersulphate works in much the same way as chlorine or bromine in that it kills bacteria and breaks down bather waste. However, unlike chlorine or bromine, monopersulphates don't produce by-products that irritate the skin or eyes and cause nasty smells.

Active Oxygen (O2) tablets are used in conjunction with a weekly does of a liquid activator  which also acts as an algaecide.

How often should I add the liquid?

Weekly.

How often should I add the tablets?

Before you use your hot tub or weekly if it is not used.

When should I test the Active Oxygen level?

Always test one hour after application of the O2 tablets. The reading should be 5 - 10 ppm one hour after application.

What TA and pH levels should I maintain

When using O2 as a sanitizer you shoukld maintain the following water balance:

  • TA 80 - 160 ppm
  • pH 7.0 - 7.4
  • Total Hardness 250 - 500 ppm

Do I still need to use a shock treatment?

Yes. A shock is necessary with any hot tub water treatment system because there is no other way of removing dissolved organic contaminants, such as perspiration, body oil or make-up, from the water. You should shock weekly or fortnightly, depending on your hot tub use.

You can shock the water with a double dose of O2 tablets if you wish, but use of a chlorine-based powdered shock, such as Spa Shock Express, will be more effective and so will extend the period between water changes.

How important are the filters?

Filtration is a vital part of keeping your spa water crystal clear. In common with any sanitising system, you should make certain that your filtering cycle is adequate for your spa volume and usage. Clean your filters regularly using a proprietary filter cleaner and replace them every 6 - 12 months.

Filters last longer if they are allowed to dry out properly between uses so it's a good idea to keep a spare set and rotate them.