Sanitizer	Technology	Test Available	Odorless	Effectiveness	Economy	Ease of Use
Bromine Tablets	Halide	Yes	No	Excellent	Good	Good
Cleanwater Blue	Copper Ion	Yes	Yes	Excellent	Excellent	Excellent
Nature2	Silver Catalyst	No	Yes	Very Good	Good	Good
Other Systems --the good, the mediocre, and the ridiculous (facts about them below).

Bromine Tablets

Bromine is a member of the chemical family of halogens, which also includes chlorine. This family of products kills microorganisms including bacteria by attacking their cell walls through oxidation.  They destroy the enzymes and structures inside these cells, which then renders them harmless.

		Bromine tablets for hot tubs are metered out in a convenient Floating Bromine-Chlorine Feeder such as this adjustable model #AC1001.

Advantages

Our Bromine Tablets are EPA registered, an excellent sanitizer, and are relatively inexpensive to use.  It is easy to monitor the bromine level using Bromine 3-way Test Strips to assure proper sanitation. With our floating feeder, bromine can be used in virtually any spa.  Bromine is superior to chlorine in that once free chlorine is combined with waste, it has no further sanitizing capability.  Bromine can be reactivated with OxySpa non-chlorine shock. 

Disadvantages

Although most people prefer its milder odor to that of chlorine, bromine is not odor-free.  Some people may have a sensitivity to bromine.  It tends to dry the skin in some individuals.  Recently there have been some health concerns raised regarding halogen sanitizers.  Bromine degrades upon exposure to sunlight.  Direct contact may cause discoloration of jewelry. Requires frequent testing and adjustments.

Notes

For initial effectiveness, Granular Bromine should be added at startup to assure an immediate bromine bank or reserve.  Requires regular shocking with OxySpa. Comparable in cost to other systems.  Actual cost will depend on spa size and use pattern. Read and follow all product label directions and cautions.

Cleanwater Blue System

	Cleanwater Blue is a unique EPA registered liquid bactericide/algicide. It is mineral product which kills bacteria and algae by introducing copper ions into the water. These ions, delivered by way of its proprietary carrier molecule: CW-286, disrupt the cell structure and chemical makeup of microorganisms, eliminating them in a safe way.

Since ancient times, drinking water vessels were often made of copper to help keep it fresh.  And while crossing the plains, American settlers put copper pennies in their water barrels to inhibit stagnation, although no one really understood why or how it worked at the time.

Now the purifying properties of copper have been taken a huge step further. A unique molecular activity-enhancer: CW-286, has been developed which radically boosts copper's purification power in a new way. The CW-286 carrier molecule has numerous negatively charged attachment points which hold Cleanwater Blue's positively charged copper ions, and keep them highly potentiated and biologically active. When bacteria or algae contact potentiated Cleanwater Blue CW-286 molecules, copper ions are released which they quickly absorb. This destroys microbes by disrupting their cell structure.

Advantages

Cleanwater Blue is odorless and an excellent bactericide.  It also eliminates algae, so there is no need to buy a separate algicide.  The liquid is concentrated, so it's very inexpensive to use.  It is easy to monitor the copper ion level using Copper 3-way Test Strips to assure proper sanitation.  Cleanwater Blue will not dry or irritate skin, cause eye redness, or fade bathing suits.  Unlike bromine or chlorine, this product will not degrade spa cover vinyl or floating thermal blankets, nor will it degrade liners in soft spas, or cause discoloration of jewelry.

Spa water properly treated with Cleanwater Blue is safe to people and pets, since the copper level required in your hot tub is actually lower than the standard set by the EPA for drinking water.  Depending upon your spa size and use pattern, one bottle can last up to 6 months. Very low maintenance effort-- water is tested and adjusted just twice a month.

Disadvantages

Although Cleanwater Blue has no significant disadvantages, it is not compatible with conventional stain, scale, and metal reducers, since these products will reduce the beneficial copper ions.  Use only Cleanwater Purge stain & metal inhibitor with Cleanwater Blue. Do not use synthetic clarifiers with this product.

Notes

Prepare water with Cleanwater Prep calcium sequestrant.  Requires regular shocking with OxySpa non-chlorine shock. Ozone compatible. Compatible with chlorine (and bromine), so Dichlor Granular Chlorine may also be used at startup, and as an occasional shock if needed. Sea Klear Natural Clarifier is the recommended clarifier. Read and follow product label directions and cautions. Product must be stored above 32º F.  Read more about Cleanwater Blue (pdf)

Nature2 Cartridge

The Nature 2 spa purifier unit fits inside your hot tub's filter cartridge. It contains a silver catalyst-- crystals inside of a plastic cartridge.  It works by producing positively charged ions that attack and destroy the negatively charged cells of microorganisms, as water flows through the cartridge.

Advantages

Nature2 is very good mineral purifier with a reasonable cost to use.  It is odorless, will not dry or irritate skin, cause eye redness, or fade bathing suits.  Nature2 is safe to people and pets. Unlike bromine or chlorine, Nature 2 will not degrade spa cover vinyl or floating thermal blankets.

Disadvantages

There is currently no practical way for users to test for silver ion content, so care must be taken to ensure proper sanitation.  Will not work with all spa filters. (Minimum required filter length is approx. 7".  Minimum filter hole diameter is 1-1/4").  If your filter is too small to accommodate the Nature2 unit, you cannot use this system. 

Notes

Requires regular shocking with OxySpa. Sea Klear is the recommended clarifier. Not compatible with bromine, so if converting from bromine, be sure to drain and clean your spa prior to use of Nature2. Requires circulating of your spa water at least 4 hours per day. Lasts 4 months.  Upon startup, and when water quality problems arise, water should be shocked with Dichlor Granular Chlorine. Read and follow all product label directions and cautions.

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Other Systems
(What you need to know before trying them)

Chlorine

We do not recommend chlorine as a primary spa sanitizer.  It is better for use as an occasional shock, but if you choose to use it for sanitizing, select the only chlorine form that is suitable for spas: Dichlor granular.  Since Dichlor does not come in tablet form and so cannot be used in a floating tablet dispenser, your spa will have to be more frequently dosed and tested.  NOTE: Trichlor and CalHypo tablet are approved for pool use only.  Household bleach is not suitable or approved for use as a spa sanitizer. 

Spa Secret

Spa Secret purifier s a good supplemental product.  It is not EPA-registered as a standalone sanitizer, so must be used in conjunction with bromine or chlorine. Also sold under the name Spa Genie, which is identical and made by the same manufacturer.

Spa Frog Systems

The Frog mineral purifier stick is a very good product, and must be used in conjunction with a residual bromine or chlorine sanitizer.

The new Spa Frog Floating System is a good 2-part product for reducing bromine use, without totally eliminating it.  It combines both a bromine sanitizer cartridge, as well as a mineral cartridge, which attach to a convenient float.

Some spas come factory-equipped with this same concept in an in-line, in-spa design.  We have the best prices on Spa Frog In-Line Refill Cartridge Kits.

Ozonators

Ozonators are excellent devices for helping to maintain good hot tub water quality and purity, but they are not standalone sanitizer systems. Ozone works in conjunction with your sanitizer system to improve and purify the spa water by oxidizing soap, deodorant, hair spray, cologne, makeup, perfume, body lotion, hand cream, sun tan lotion, saliva, and urine.

Biguanides

There are several brands of Biguanides on the market (chemical name: polyhexamethylene biguanide or PHMB) such as BAQUACIL® and SoftSwim®.  We do not offer them because of lack of compatibility with other spa chemicals, and because they tend to be more expensive than other sanitizer systems.  Their use may require other proprietary companion products such as special filters cleaners, etc.  Biguanides may erode certain plastics such as polycarbonates.  Many users report problems with algae slime that are difficult to eradicate.

Silspa

This silver-based liquid product is no longer supported by us.  We recommend Cleanwater Blue as an excellent replacement.

Electric Spa Ionizers

These units produce metal ions by passing an electric current through spa water between two electrodes.  As the water passes over them, ions are displaced from the electrode plates and circulated.  We do not recommend Electric Ionizers for spas for several reasons. They have a substantial initial equipment cost and usually require modification to the spa's plumbing, which may void your warranty.  These systems can be prone to maintenance problems.  They also require periodic replacement of the electrodes as they are depleted.  The ion levels can also be problematic to monitor for proper sanitizer level.  Since these systems run on electricity, this cost should also be factored when evaluating them. Some promoters of these ionizers tout them as "chemical free" systems.  This is a falsehood, since by definition, metal ions in water are chemicals.  They merely use the spa as a mini chemical factory to produce the ions electrically, rather than pour them from a bottle.  A chemical shock must still be added to oxidize organic matter and dead cells.

Salt Water Systems

These systems generate chlorine by passing an electric current through salt water, between two electrodes. Salt (sodium chloride), which is added to the spa water, is the source of the chlorine for the process. Although gaining popularity in pools in parts of the world, we do not recommend their use in spas for several reasons. The equipment is expensive, and may require modification to the spa's plumbing, which may void your warranty.  These systems can be prone to maintenance problems and require periodic replacement of the electrodes as they corrode away.  Since these systems run on electricity, this cost should also be considered. Some promoters advertise them as "chemical free" systems.  This is a falsehood , since the chlorine produced is obviously a chemical, as is the salt itself.  They merely use the spa as a mini chlorine factory.

Hydrogen Peroxide

We do not recommend hydrogen peroxide for use in home spas for a number of reasons.  Unlike the 3% drugstore variety, commercial-grade peroxide strong enough to be effective in pools or hot tubs ranges from 25% to 35% concentration. It can be dangerous to store, transport, and handle.  Although it does a fair job of controlling bacteria at 30-40 PPM, it must be monitored very closely, because at excessive levels it can burn lung and eye tissue. It can prove to be more expensive to use than other systems.

Magnets

Unbelievable but true-- and though hardly even worth mentioning, there are a bolt-on magnets offered to consumers with claims that they can reduce spa chemical usage, stabilize pH, and reduce odors by "magnetizing" the hot tub water.  This is pure junk science-- there is no valid empirical data to support these claims.  Don't waste your money on these dubious devices.

Rainforest Blue

We do not recommend this product since the introduction of the advanced Cleanwater Blue system. We've heard reports of problems with staining, and performance issues, especially with well water or water with significant calcium content. These problems have been overcome with the introduction of Cleanwater Blue, which has a highly advanced carrier molecule: CW-286. This carrier optimally potentiates the copper ions, and works in unison with Cleanwater Prep to sequester excess calcium.  Cleanwater Blue bactericide/algicide also requires less monitoring and testing-- adjusted just twice a month. NOTE: Rainforest Blue is no longer legal for sale in most states.