Hot Tub Life Articles

Freedom! Are you ready to give up chlorine and bromine?

Alternative Sanitizers are finally gaining acceptance and catching the attention of many pool and spa owners !

There once was a time, long long ago, when the only thing that pool & spa owners could use to keep their water clean was chlorine. It was cheap and it actually worked pretty well. But there was that strong chemical odor to deal with. Hey, that’s how a pool should smell, no? People put up with it because there was no alternative.

Then hot tub spas started to become more popular in the 1980’s. As soon as more people started installing hot tub spas in their homes, the odor and harshness of chlorine began to cause more and more discomfort. It’s one thing to smell like a chlorine tablet when you get out of an outdoor pool, but it becomes much less acceptable after a long soak in your indoor hot tub! Another thing started to become more apparent when large scale use of residential hot tubs increased - chlorine, it turns out, is not really a very good sanitizer in water over 100º. It drastically loses effectiveness as a sanitizer in hot water and, as a result, people started adding more and more chlorine to their spas in order to keep the hot water fresh and clean. That, of course, produced more chlorine odor and the whole thing made hot tubbing a less than pleasurable experience. Something had to be done !

Enter Bromine. Bromine was great. It worked best at temperatures between 90° and 110° and it was practically odorless. This seemed to be the perfect way to sanitize a hot tub. Bromine really became very popular in the mid 1980’s and is still the most widely used hot tub spa water sanitizer. The only problem with it was that it only worked effectively within a narrow PH and Alkalinity range. Many tub owners were having problems keeping their pH and Alkalinity adjusted properly - and as a result their water was not always staying clear and fresh. Additionally, Bromine cannot really be used effectively in a swimming pool because it is rapidly "burned off" by the sun, leaving the pool with little to no sanitizer.

The Ozone Generator was the next major sanitizing innovation which was introduced in the mid 1980’s. Instead of relying on only chemicals that were added to the pool or spa each week, the Ozone Generator actually produced Ozone Gas which is injected into the water via the return jets. Ozone is 3000 times more powerful than Bromine or Chlorine and is a powerful oxidizer which almost medically sterilizes the spa water. Ozonators do work very well, however you still need to keep your pH and Alkalinity levels within the proper range and you still need to add a "backup" sanitizer to the water (either a small amount of Bromine or Chlorine). Further innovation was still needed to get us closer to a truly "automatic" water sanitizing system.

Now it has been almost 20 years since the Ozonator has been invented - and there still is no “perfect sanitizer” for pools or spas.

There have been many “Alternative Sanitizing” systems that have been introduced over the last 20 years. Although no single product can do everything chemically for a pool or hot tub spa, these Alternative Sanitizers sure go a long way to making pool & spa care much easier - and pool & spa use more pleasant.

The main things that consumers complain about when it comes to their water chemistry problems are (in order): “chemically” odor, “musty” odor, burning eyes, coughing from fumes, bleached bathing suits, hard to balance water, hard to balance PH and/or Alkalinity, water turns green, water is always cloudy, blonde hair turns green !

It would be nice if someone would invent a pill that you simply drop in a pool or spa and it sanitizes the water, adjusts the PH, clarifies, deodorizes and shocks the water too - and you just need to add this magic pill once a month ! Now that would be an invention that would make millions ! Unfortunately, in the year 2002, there is no such thing.

So a number of manufacturers have come up with a variety of products that are now officially known as “Alternative Sanitizers”. We will try to give you a brief overview of each type of product - noting the positive and negative points of each. If you go shopping for Alternative Sanitizers, be a little wary of dealers that only sell one type of Alternative Sanitizer and tell you “this is the best one in the world”. Truth be told, they all have their good and bad points, and it is ultimately up to you to select the right one for your pool or spa.

Oh, one more thing. There is a legal and governmental definition for what is “officially” considered a “sanitizer”. Accordingly, most Alternative Sanitizers shouldn’t really call themselves “sanitizers” at all. A product or chemical must get EPA approval to be officially called a “sanitizer”. Most of these products are not actually EPA approved as sanitizers and should use the term “water conditioner” instead. That is in the legal world. But in the real world, most pool & spa guys - as well as consumers refer to them as Alternative “Sanitizers”. You just have to remember to also add another sanitizer (shock) to the water once per week.

Ultraviolet (UV)

Believe it or not, the ultraviolet portion of the sun’s radiation and sunlight is actually a great way to kill bacteria in pools or spas. Who knew? UV Sanitizers use the destructive radiation of these ultraviolet waves to kill any and all live bacteria or algae in water. A small glass chamber encloses powerful UV light bulbs and as the water passes through the tube, the bacteria are killed by the concentrated waves. It almost sterilizes the water. You are thinking “that’s great, let’s run out and get one”. Wait a second...hold your horses. The down side to UV is that it does nothing for water clarity, so you still get cloudiness - and it leaves no residual disinfectant in the water. That means you still have to add a backup sanitizer to the pool or spa (chlorine or bromine). The good part is that it will definitely reduce the amount of chlorine or bromine you need to add. That is the main benefit of UV.

Biguanides

The actual chemical name of this type of sanitizer is polyhexamethylene biguanide. It is most commonly found in “Baqua” type products. You can use it in a pool or spa and it contains no chlorine or bromine. It’s claim to fame is that it is very gentle on the skin and eyes. Some contact lens cleaning solutions contain biguanide ! Unlike UV, it stays active in the water for a long time and is an effective killer of bacteria and microorganisms. You still need to manually adjust the PH & Alkalinity of the water each week and you also must shock the pool or spa weekly with a “non-chlorine” shock. The only danger with Biguanides is that you cannot mix them with chlorine or bromine. It’s somewhat difficult to “switch back” if you find you do not like the way the Biguanide works. There are special chemicals you must add to the water in order to switch back.

Ionizers

When you release copper and silver ions into water, they kill all bacteria and algae. The Ionization Unit allows water through a tube that electrifies copper and silver alloy anodes, which produces positively charged particles in the water. These mineral ions then go about their business killing everything in their path ! The PH adjusting is easier and less necessary with Ionizers because the ions do not effect the acidity of the water. Ionizers can be used in pools or spas. You still need to shock the water weekly and you may need to add a clarifier as well. Overall, this is not a bad system, although the silver/copper must be replaced periodically. 

Ozonators

Often confused with Ionizers because of the name similarity, Ozonators work on a totally different principle. Ozone is a gas (like the “ozone layer” around the earth) that is produced by ultraviolet light (UV) exposure to oxygen. When ozone gas is injected into pool or spa water, it acts as a very powerful sanitizer and will kill off almost all of the bacteria present. Ozonated water will remain clearer longer than just using bromine or chlorine as the primary sanitizer.

Ozone water purification is 3000 times more powerful than ordinary water sanitizers (bromine or chlorine). It does not give off that "chemical smell" normally found in pools and spas and tends to produce less skin and nasal irritation. An ozonated hot tub spa can usually go longer between water drainings than a spa using other sanitizer chemicals. With swimming pools, you will use much, much less chlorine than you used to.

How does it work you ask ? There are two types of Ozonators. One type produces the gas through Corona Discharge (electrically charging the particles) and the other ozone generator contains an ultraviolet light bulb (much more common). 

On UV-style ozonators, the unit sucks in oxygen from the surrounding air and exposes it to the UV light source. The oxygen “O-2” is transformed into ozone gas which is "O-3" gas. This gas is then sucked into the jet piping of the pool or spa by the "venturi effect" which creates a suction that shoots the gas into the water. Some ozonators also have a compressor which aides in the gas injection. The O-3 gas then goes to work attacking any bacteria present in the water. Two of the oxygen molecules are used up during the chemical reaction and the third oxygen molecule is released back into the air. That molecule accounts for the "fresh" or "sweet" scent that is often noticed coming from ozonated water.

They make Ozonators in all different sizes depending on how many gallons of water you need to sanitize. You still have to add a small amount of a back up sanitizer to the water and you must shock the water weekly as well. The PH is not directly effected by the ozone gas, but you will still need to test and adjust that each week too. Generally speaking, the smaller Ozonators tend to work much better in hot tubs than swimming pools because there is much less water to deal with. Also, most hot tub spas are not exposed to direct sunlight all day, whereas most swimming pools are. 

To make up for these factors, ozone manufacturers have come up with Ozonators made specifically for swimming pools. These units are substantially larger (and more costly) than hot tub Ozonators, however they can output a much larger amount of ozone gas per hour and are thereby sufficient for most pools - even outdoors !