Non-Toxic Sanitizing

With a soaking tub, as in anything, cleanliness is next to Godliness, and how you choose to deal with sanitization has a far-reaching affect on the overall satisfaction youll receive from your soaking tub. Using harmful chemicals such as chlorine or bromine are contrary to the very purpose of a soaking tub, because they undermine the natural and healthy quality of the experience. At Island Hot Tub Company, we recommend an easy and effective method of maintaining pristine water quality without harmful chemicals. This allows you to enjoy the rejuvenating benefits of your soaking tub with complete confidence.

Whats the problem?

Bacteria from human bodies are the primary health concern in any tub. However, in a freshly-filled tub of water, bacteria are diluted to such a low concentration, they are not a significant problem. Only when bacteria are allowed to multiply in warm water, along with organic matter from the skin, do they pose a health risk. The primary need for sanitizing, therefore, is not while people are in the tub, but after they get out.

Many Chofu customers avoid water-sanitizing problems altogether by draining their soaking tub after each use (most practical with low-volume tubs). But for those who wish to conserve the water for longer periods, its absolutely necessary (as with any spa or hot tub) to use a sanitizer to eliminate bacteria.

Whats the solution?

To maintain the natural integrity of a soaking tub, we recommend using only sanitizers that kill bacteria without harming people. Weve found only one substance that meets this requirement oxygen, in the form of oxygen ions (O1), also referred to as ìunpaired oxygen.î This substance is elegantly simple to use and very effective. An interesting fact: it is several thousand times more potent than either chlorine or bromine.

Unpaired oxygen is found in both hydrogen peroxide and ozone. Both do an excellent job of killing bacteria, but most importantly, they leave no harmful residue. They both kill bacteria by releasing oxygen ions (O1) into the water. When the reaction is completed, oxygen atoms (O1) have joined together to form stable oxygen molecules (O2). The process is quick, safe, and sensible.

Hydrogen peroxide

Hydrogen peroxide (H2O2) is a truly amazing and wonderful sanitizer. For the soaking tub, it should be used in a high-strength 27% solution (not the 3% variety that comes in the brown bottles). When poured into a soaking tub, hydrogen peroxide immediately disassociates into water (H20) and oxygen ions (01). These ions are so unstable that they quickly attach to anything within reach, destroying bacteria on contact. Within several hours the reaction is completed, leaving stable oxygen (O2) and water (H2O). Beautiful!

How to use it

To sanitize a soaking tub, hydrogen peroxide is thoroughly mixed into the water at 1/4 to 1/2 cup per 100 gallons. CAUTION: Concentrated hydrogen peroxide is a powerful oxidizer which can cause skin burns when poured directly from the bottle. Care must be taken to follow all indicated precautions on the bottle.

Maintenance dose

Hydrogen peroxide is also safe to use while people are in the tub (our white blood cells secrete it to kill invaders). To control bacteria, pour in 1/8 cup H2O2 per 100 gallons of water a few minutes before people get in.

Where to get hydrogen peroxide

Hydrogen peroxide is available at most spa stores, under the category of oxidizers or shock treatments. Since it is sold as a cleaning agent, most spa stores are unaware of its value as a sanitizer. Several brands dont even indicate the contents on the bottle. (A Federal MSDS Report can be requested from any manufacturer for a list of ingredients and potential health hazards.) These three brands are certified to contain 27% hydrogen peroxide:
1. Clear Comfort Clarifier
2. Soft Swim-C (Soft Swim-B is only 15%)
3. Baqua-Shock


Ozone (O3) is stable oxygen (O2) with an added oxygen ion (O1). An electrical device called an ozone generator, or ìozonator,î is used to inject microscopic ozone bubbles into tub water to kill bacteria. Ozone sterilizes water in essentially the same way as hydrogen peroxide by releasing unpaired oxygen atoms (O1) into the water. As with hydrogen peroxide, O1 seeks to become stable by attaching to itself to another molecule. While ozone is effective at killing bacteria in water, it is not as effective for sterilizing tub walls because ozone bubbles do not make good contact with surfaces. Therefore, hydrogen peroxide must also be used to sterilize tub surfaces if water is kept for an extended period. Many people who rely strictly on ozone for sanitizing will change their tub water frequently.

Island Hot Tub offers an effective ozone generator made by the Clear Water Tech Co. It plugs into an 110-volt outlet and delivers ozone into the water through a long plastic tube placed over the side of the tub. It must be used in conjunction with our self-contained filter pump to assure thorough distribution of ozone in the water.

Sanitation is easier with demand-heated soaking tubs

When it comes to keeping water sanitized, demand-heated tubs with Chofu heaters have a great advantage over spas:
1. Since water volumes are usually lower, it becomes practical to drain the tub frequently, and sanitation is much easier when water is kept for only shorter periods of time.
2. Water that is not kept continually warm is much less conducive to bacteria growth, requiring lower levels of sanitizers.

How to maintain a healthy soaking tub

1. Encourage tub users to shower before entering. This will eliminate most of the loose organic matter and oils from the skin.
2. Use non-toxic sanitizers: high-strength hydrogen peroxide or ozone.
3. Sterilize the water immediately after the tub is used to kill bacteria before it can start multiplying.
4. Drain and clean the soaking tub frequently.
5. Apply a weekly maintenance dose of hydrogen peroxide if water is kept in the tub.