Swim Spas - How to Effectively Treat Them

by Pool Builders on 08-22-2009 in Articles

A Swim Spa is both a swimming pool and a spa or hot tub. And it's neither! What? Let's look at what makes them unique to care for & treat.

Pool similarities:

- "cooler" water - typically 85 degrees - 95 degrees F
- "larger" bodies of water
- "larger" surface areas & equipment

Spa / Hot tub similarities:

- "larger" & more plumbing area
- "smaller" body of water - compared to even a small above ground pool - usually between 1500 and 3000 gallons
- "larger" bather loads - number of people per gallon using the swim spa.
- "warmer" water - compared to the average swimming pool at about 80 degrees F
- "aerated" water - lots of bubbles & infused air into the water system (leads to more gassing or aerosolizing of care chemicals)
- water is typically heated MOST of the time (especially indoor swim spas)

Not only those differences but you also need to take into consideration if the swim spa is used indoors and year round or outdoors and seasonal. Now, what do you use to treat it? Let's look at the basics & how they work:

- Chemical Used: Chlorine - dichlor granular; Overall Effects - Good; Special Notes - needs to be added multiple times per week; can also be used as a shock treatment; ability to "control" the amount of chlorine better; maintained at a level of 1.0 - 2.0 ppm
- Chorine - trichlor tabs/sticks; Good; may put a drag or constant lowering of the pH; added using a floater or chlorinator; maintained at a level of 1.0 - 2.0 ppm
- Bromine tablets; Good; sometimes gives a "musty" odor; added using a brominator or floater; maintained at a level of 2.0 - 4.0 ppm
- Liquid Chlorine; Not so good; significantly adds to Total Dissolved Solids (TDS), resulting in more frequent draining & refilling
- Salt / Chlorine Generation; Not so good; High mineral levels, scaling of surfaces, plumbing, heaters, etc.
- Biguanides (such as BioGuard Soft Swim or Arch Chemical Baquacil); Not so good; significant foaming, water can feel "gummy" if PHMB is allowed to be "high" (over 50 ppm)
- Ionizers (such as Nature2 or Pool Frog); Good; may not provide sufficient sanitizing when larger bather loads are encountered
- Algaecides; Not so good; significant foaming of the water; algae better controlled with borates and solid chlorine levels
- Cal Hypo Chlorine; Almost bad; significantly adds to Calcium Hardness & Total Dissolved Solids (TDS), resulting in scaling and more frequent draining & refilling
- Borates (such as Optimizer Plus or Proteam Supreme); Good; controls algae growth without foaming plus aids in overall water balance; easy to maintain (at a level of about 50 ppm), typically added 1 or 2 times per year.
- Natural Bio-film Removing Products; Good; prevents & controls bio-film build-up in plumbing lines and on surfaces; Pool Pucks are added every 2 weeks
- Pool Moss products; Good; prevents & controls bio-film build-up in plumbing lines and on surfaces; sphagnum moss packets are changed monthly
- Enzymes; Good; help "digest" excess swimmer waste that will contribute to bio-films, odors, etc.; added weekly
- MPS (potassium mono persulfate) shock; Good; usually used in combination with Ionizers; not a stand-alone product; a good oxidizer but poor sanitizer; recharges bromine; breaks up chloramines
- Household products? Stay away from them. They are NOT pool or spa chemicals. Would you cook or do laundry with pool chemicals? Didn't think so.

Remember that good water balance (pH, total alkalinity & calcium hardness) is just as important for a Swim Spa as for a swimming pool or hot tub. Good water balance affects sanitizer efficiency, equipment longevity and swimmer or bather comfort (red eyes, itchy skin, dry hair, rashes, etc.) and health.

With all of this information, let's put it all together for simple care & effective care.

First what do we want to accomplish? We want crystal clear water that is well balanced, bacteria & algae free, that will be friendly to the equipment, easy on our bodies, simple to maintain, and cost effective.

Second, what combination of chemicals (a care system) works best? Over the past 2 years we've been helping customers with swim spas determine the best care program for their individual needs and addressing their individual concerns. For all swim spas, be sure to maintain a chlorine level of about 1.0 - 2.0 ppm or if using bromine, 2.0 - 4.0 ppm.

Simplest & most economical - Chlorine plus. Granular dichlor chlorine or slow dissolving trichlor tablets plus a borate product such as (maintained at about 50 ppm to inhibit algae growth). Shock monthly with a MPS (potassium mono persulfate) shock. A weekly dose of a good quality natural enzyme such as digest "un-filterable" swimmer waste, added weekly. Bio-film removal and preventing products remove build up in the extensive plumbing lines & jets of the swim spa leading to decreased chlorine use, cleaner filters, better "feel" & increased swimmer comfort.

Simple & a little more - Ionizers plus. Ionizing system cartridges are installed & replaced about every 4 months according to manufacturer's instructions. Again, a good borate product as mentioned above - maintained at about 50 ppm to inhibit algae growth. Shock every week with a diclor or blended dichlor (helps maintain low level of chlorine) shock. Pool enzyme product (follow label directions) to digest "un-filterable" swimmer waste, added weekly (per 2,000 gallons). Bio-film removing products further prevent bio-film build up in the extensive plumbing lines & jets of the swim spa leading to decreased chlorine use, cleaner filters, better "feel" & increased swimmer comfort.

A more natural solution - Pool Moss products plus chlorine. Although Pool Moss is a newer product, the initial results are outstanding. The "tea" from the sphagnum moss aids in controlling bacteria & bio-films causing the chlorine to last significantly longer. The water stays more "naturally" balanced, softer feeling and better smelling. Please see my article on Using Sphagnum Moss.

Great looking and feeling water (not to mention " healthy" and sanitary water) is possible and easily achieved. Happy swimming and soaking!

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