If you don't have a chlorine generator on your spa, time to get one. You will be amazed!

Best price online, click image above.

There are a few things you can look for that will tell you it’s probably time to change the water in your spa. If you are noticing a build up of foam caused by your jets then you should do a partial drain. (THIS IS ONLY A TEMPORARY FIX)
If your water is cloudy then I would first make sure the chemicals are correct. In this case draining isn’t always essential.
If you use your spa often, one suggestion is drain your spa 12’’ every week. If not, 12’’ every few weeks would help to eliminate completely draining.
If you keep up the chemistry correctly, circulate the water often, clean the filters monthly and avoid drinking or eating in your spa, then you should not have to drain for three months. Quarterly draining must happen because the (TDS) total dissolved solids in your spa increase when you add chemicals. When the TDS is too high, it indicates that your chemical levels are too great and are unable to work proficiently.

But…
If you use salt chlorine generators or bromine generators, the salt in your hot tub temporarily creates a chemical to sterilize the pool. Once its job is done it turns back into salt thus creating this ongoing cycle. Leaving you with less build up of chemicals, less hazy water, less draining and more soft, clean water.

You must use non-iodized salt in your spa or pool. This pure salt prevents the water from yellowing over time. You will find that salt is sold in a variety of sizes and a wide range of scents. You can also use a water softener salt but it may take longer to dissolve because it is very similar to rock salt.

Chlorine Generator

Chlorine generators make chlorine from salt in your pool or spas water. You simply add salt to the water and the chlorine generator does the rest. The typical salt concentration is 2000 to 4000 ppm, at 3000 ppm that is about 2 pounds of salt per 100 gallons of water. Chlorine generators are very popular because they eliminate the buying, storing, transporting and handling of chlorine as well as provide a dramatic reduction in the maintenance demands of your pool or spa.

Self Cleaning

The chlorine generator has titanium plates with a special rare-earth coating that can have a build-up of calcium or other compounds over time. That is because during the electrolysis process current goes in one direction from plate to plate. Chlorine generators with the feature of self cleaning periodically reverse the direction of the current which helps to break up the compounds that have attached to the plates. If the hardness of the water is very high even self cleaning chlorine generators may still need to be cleaned, but not as often as those without self cleaning.

Adjustable Power

Chlorine generators typically operate at full power. To adjust the power they adjust how long they are on. A chlorine generator operating at half power may be on for 12 hours in a day, and off for 12. Chlorine generators without adjustable power usually need a timer added so you can externally control the amount of chlorine produced. Without controlling the chlorine production you can end up with too much chlorine. You can also adjust the chlorine production by increasing/decreasing the salt level but this can be a hassle.

Slow Chlorine Production

Chlorine generators make chlorine slow and are usually rated in production terms of ounces per day or pounds per day. If you need to shock your water usually chlorine has to be manually added as a chlorine generator can’t make a lot of chlorine all at once.

Other Chemicals

Chlorine generators have less effect on the overall water chemistry than other forms of chlorine reducing the need for water balancing chemicals. Chlorine generators also make chlorine every day reducing the chance that there will be days without a sanitizer which also reduces the chances of green water. The electrolysis process of a chlorine generator does tend to increase the pH so with a chlorine generator you will need to measure and adjust your pH every week.

Chlorine Generator Sizing

The titanium plates in a chlorine generator are expensive and the most expensive part of the generator. Units with higher chlorine production usually have more titanium plate area and are therefore more expensive. The most common chlorine generators are in-line, meaning they are plumbed into the piping of the pool/spa equipment. This also means they can only be on when the main circulation pump is on, or water is flowing across the titanium plates. If your chlorine generator has a low production rate you may have to run your pump longer to get the desired chlorine level.

Convection Chlorine Generators

This type of chlorine generator isn’t plumbed into the existing pool/spa equipment and isn’t tied to the existing equipment in any way making installation very easy. Usually, just plug in the power supply to a GFCI protected outlet, and then hang the chlorine generator cell over the side of the pool/spa into the water. This type of generator can have a lower production rate as it doesn’t require the existing circulation pump to be on.

Life Span

The coating on the titanium plates determine the life span of the cell and it typically 10,000 hours of chlorine production. This life span is dependent on the current going through the plates and as the current goes up, the life drops.

In the last 2 weeks, I have been hearing a lot of people asking about chlorine generation for hot tubs. They know about chlorine generation for swimming pools and think it is a wonderful idea to have a chlorine generator for their hot tubs.

The process works very well for hot tubs. I actually used swimming pool sized systems on larger, commercial spas in health clubs with great success.

Many a spa problem or spa trouble can be linked to improper spa maintenance. Always follow the spa owners manual when It comes to spa maintenance. You may be surprised that once you have your spa that it takes a lot more time in spa maintenance than you were expecting. If the chemical balance is far off it may take some time to bring the chemical  balance back into balance. The addition of a chlorine generator to the spa install has been found to drastically reduce the spa maintenance. A chlorine generator requires adding salt to the water hence making salt water. The salt water lasts a very long time before more needs to be added and typically the only thing you need to watch out for in spa maintenance is the pH level.

Bacquacil ( Baqua Spa ) or Soft Swim Biguanide Treatment

Originally developed as an anti-microbial scrub, is a totally engineered chemical, poly-hexa-methylene-biguanide (PHMB) was patented in 1977 and marketed for pools and spas under the name Baquacil. This technology has the distinction and the EPA approval as the only non-halogen sanitizer available for pools and spas for residential use.

Now that the patent has expired, another line of biguanide products is being marketed under the name Soft Swim. As a full system for complete halogen free water care, these products are a stand alone alternative to traditional sanitation methods. The Biguanide itself is combined with algaecides and hydrogen peroxide for periodic oxidation. The system tends to gum up filters, and of course a product is available to de-gum it. Biguanides are not recommended for spas or aerated pools. As long as you don’t add any other chemicals but those recommended by the manufacturer everything will be ok but Biguanides are incompatible with TSP, ozone, detergents, ionizers, and other common pool and spa chemicals.

At recommended concentrations, biguanides won’t irritate the skin or eyes. It does not create noticeable irritating byproducts like chlorine, but there are reports of invisible vapors arising from spas treated with Biguanide that cause an unpleasant tickling in the throat, or more severe coughing, or may even build up to the degree that a person in the spa is unable to breathe.
Baquacil. It is more expensive than chlorine, and much more difficult to use. There are other negatives to consider. It seems that after what could be a very short time, the water quality starts to decline. In addition, there have been reports of strange infestations occurring in pools on the Baquacil program. If this happens, you will probably have to drain the pool and start over again.
Unfortunately, the Baquacil or Soft Swim leaves behind a slimy, sticky residue that covers the entire surface of your pool or spa and permeates all your plumbing, so simply draining the water does not eliminate this problem. It takes an acid based cleaner to dissolve this slime, and may necessitate lots of scrubbing and/or multiple cleanings to completely get rid of it.

The post above is some general information on this product. Since I have never personally used Baquacil or Soft Swim products, I suggest you do your own search on Baquacil to read some of the comments posted by actual users.

The issue of corrosion continually comes up as a mystery and it really doesn’t have to be. Before chlorine generators arrived on the scene here in the US, we had regular old pools and spas that had corrosion issues. Many of these pools & spas were treated with liquid chlorine and had high TDS levels. The reason for this is that high TDS levels increase conductivity, letting stray currents to run through the water. Further investigation with sensitive instruments revealed that these bodies of water were not grounded properly. This was the cause of the corrosion. The only practical way to deal with this was to place zinc balls in the skimmers and inspect them monthly to make sure there was no scale buildup as this makes them ineffective and they will need to be acid washed so they will do their job, which is to help neutralize the stray currents in the water. Ocean boats use zinc anodes to prevent corrosion but here the salt concentration is 10x higher. It takes such a small amount of current that most people would never even detect its presence. This problem is much easier to deal with in a hot tub as you can make sure it is properly grounded with minimal effort. For extra peace of mind, you can always place a zinc ball in your hot tub’s skimmer.

Just about every major pool and spa equipment manufacturer has chlorine generators in their equipment line ups. In fact, chlorine generators are now being purchased on 50% of all the new pools being built in the US. Most of these have gas fired heaters which creates a hot water environment in the presence of a very soft metal (copper) and there are no salt water corrosion issues with these applications. I have personally installed and maintained salt water spas in health clubs and not found corrosion to be an issue.

I know of several hot tubs that have been on chlorine generation for 3 years or more without any signs of corrosion whatsoever. In fact, in our test spas the heating elements have been inspected on an annual basis for 4 years now with no corrosion damage.

What about CYA and does it prevent corrosion? This can be a controversial subject but here is the reality. CYA is not recommended for spa use because it lowers the ability of the chlorine to oxidize which is measured by ORP – Oxidation Reduction Potential. This can be witnessed in any pool or spa with an ORP controller. With a spa, the hot water will degrade the chlorine faster than sunlight and since I rarely ever see a hot tub that isn’t covered, why use it? CYA itself has a corrosive nature but it does lower oxidation levels which could potentially be beneficial with high levels but it also requires higher levels of chlorine to effectively sanitize. If you use CYA in a spa, it will take more chlorine to keep it sanitized. Very high levels of chlorine will cause corrosion.

The question should be why. The only reason to use cyanuric acid is to protect chlorine from uv degradation. Great when used in moderation in a swimming pool but of no real value in a spa or hot tub. Hot water and high user to water volume ratios are a much bigger factor in hot tubs and not only that but most of them are covered when not in use.

Below are 2 excerpts from the Pennsylvania Department of Health which should be evidence enough not to use cyanuric acid in your hot tub.

What are the effects of higher levels of cyanuric acid? – As the level of cyanuric acid rises, the “killing power” of the free chlorine residual weakens. At above 50 ppm of cyanuric acid, the time it takes to kill bacteria in the water is much longer compared to swimming pool water without cyanuric acid. As the level of cyanuric acid builds up, the chlorine will become increasingly less effective in keeping the water clean and problems such as increased cloudiness in the pool water, high bacterial test results, and even algae growth can occur.

Should cyanuric acid be used in hot tubs or spas? – At even moderate levels of cyanuric acid, the amount of time it takes chlorine to kill pseudomonas aeruginosa (the bacteria that causes “hot tub itch”) can be as much as a hundred times as long as in a hot tub or spa without cyanuric acid. For this reason, the Pennsylvania Department of Health does not recommend the use of cyanuric acid or stabilized chlorine in any hot tubs or spas

This is why hot tubs treated with dichlor or trichlor have to be dumped on a regular basis. As the CYA buildup occurs, it becomes impossible for the chlorine to do its job. This same effect will also happen with bromine tablets as the BCDMH found in the tablets have the same effect on bromine as CYA has on chlorine. This is why when you start with fresh water the first month is generally less trouble to maintain water quality and then it goes downhill from there.

Does CYA prevent corrosion? This can be a controversial subject but here is the reality. CYA is not recommended for spa use because it lowers the ability of the chlorine to oxidize which is measured by ORP – Oxidation Reduction Potential. This can be witnessed in any pool or spa with an ORP controller. With a spa, the hot water will degrade the chlorine faster than sunlight and since I rarely ever see a hot tub that isn’t covered, why use it? CYA itself has a corrosive nature but it does lower oxidation levels which could potentially be beneficial with high levels but it also requires higher levels of chlorine to effectively sanitize. If you use CYA in a spa, it will take more chlorine to keep it sanitized. Very high levels of chlorine will cause corrosion.

Alternative Sanitizers

Chlorine Generators: These devices contain electrical cells which generate chlorine from a bank of salt added to the pool water. After being depleted, the FAC reverts back to salt to be reused. This device is really not an ‘alternative’ system, as FAC is produced and reacts the same as adding chlorine from a purchased bucket without the added by- products that come with packaged chlorine and are dissolved in the water.

Ionizers: These are usually copper and or silver electrodes which introduce soluble copper and silver ions to the pool when an electric current is passed through the unit. Copper is used for algae control and silver for bacteria control. While once touted as “chlorine-free” systems, they are now mainly sold as devices to be used with low levels of chlorine. These ‘heavy metal’ devices (so-named because of the high density of elemental metals) are sold in the pool industry as ‘alternative’ sanitizers.

They have several shortcomings, however. First, in Canada, silver is not allowed as a sanitizer and is not even allowed to be listed in any accompanying literature. Second, although copper is an extremely effective algaecide, it has the propensity to precipitate and discolour pool surfaces with a tenacious grey to black stain. Finally, these devices are not oxidizers, so 90% of the workload of chlorine is not fulfilled.

Magnets: Using magnets as water conditioners, mainly for pH and scale control, is dismissed as a scam by some industrial water treatment associations and in a previous article by the writer. Aggressive marketing and threats of legal action often silence the opponents of magnetic devices. These devices are also sold as a way to increase gas mileage when attached to the gas tank and as a way to increase blood circulation when attached to the body by adhesive tape…. interesting.

Oxygen generators: These devices pass current between two electrodes resulting in the electrolysis of water creating two volumes of hydrogen at the cathode and one volume of oxygen at the anode. The word “nascent” oxygen is often used to give them a scientific flair. The sanitation properties of oxygen are flaunted. This weakly soluble oxygen has little – if any – ability to kill bacteria or oxidize organics and the failure of such systems was once the topic on the TV show ‘Hard Copy’.

Ozone Generators: These create 03 by passing air through either Corona Discharge (CD) or Ultraviolet (UV) Radiation. Ozone – an extremely powerful oxidizing agent – is so unstable that is must be generated at the point of entry into the pool. Due to it’s activity and low solubility, it does not leave a required residual in pool water and must be used with chlorine or bromine. It is not a stand-alone system. Allowing ozone to accumulate in enclosed areas can also compromise the health of the individual.

UV Devices: It is know that bacteria are killed when subjected to certain wave lengths of ultraviolet light. You may have seen surgical instruments sterilized under UV light. Having UV irradiate water passing through a transparent pipe in the return line may kill the bacteria in the pipe, but it has no effect on sanitizing the remaining water in the pool. YV leaves no residual and no ability to oxidize. Trojan Technologies of London, Ontario, which sells UV generators, dismisses the use of UV technology for use in pools.

Oxidative Catalysts: These devices use a cartridge attached to the return line which contains metallic copper and finely divided elemental silver. There are no electrical components. The copper and silver dissolve by erosion or corrosion. Finely divided silver is known to be an oxidative catalyst in the synthesis of certain hydrocarbons. These devices claim that they can control algae and can assist chlorine in killing bacteria. This device is incompatible with bromine sanitizers. It has no ability to oxidize. While little staining occurs with copper, it is often difficult to measure any copper residual in the water. Some critics of this device say it is a form of homeopathy, a branch of medicine, which dilutes the drug to a point where it cannot be detected and yet claims medicinal results. Claims for silver efficacy are not allowed in Canada.

Conclusion

A list of the above ‘alternative’ systems is compiled on the spreadsheet shown below. Examine it carefully and learn the beneficial and negatives of each system. Hopefully, this will assist the reader in their choice of an ‘alternative’ sanitizer.