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Spa & Hot Tub Water Chemistry 101

When you purchase your hot tub or spa, it’s easy to think only about spending your afternoons soaking and de-stressing, not about all the chemicals and general maintenance required. However, if you don’t keep up the quality of the water in your spa, other parts, such as the filters or the pump(s), will quickly deteriorate.

If you slack on the chemical maintenance of your spa, there’s a good chance that you will be in need of a repair in the near future. The cost of repairs are often far more expensive than if you simply remain on top of your water quality and generally keep your spa in good condition.

Although it does require some extra time, it’s worth it for you to properly maintain the chemistry of your spa every couple of days to prevent chemical imbalance in the water that may cause cloudy water, algal blooms, or even white water mold. These can then cause extra buildup in filters, which in turn can damage and ultimately shorten the lifespan of your hot tub pumps because they will have to work harder.

Additionally, when mold appears in the water of your spa, you often cannot get rid of it without completely draining, cleaning, and refilling your spa. Before you drain your spa due to mold, it’s a good idea to shock the water first. The amount of time and resources this takes is completely avoidable if you know how to properly use hot tub chemicals to treat the water in your tub.

By using the steps below, you will know all there is to know about keeping your spa in tiptop shape. With the proper care, you should be able to enjoy your hot tub or spa for years to come. If you have questions or would like additional information, please contact Scioto Valley or visit us for assistance.

  1. Carefully read the manufacturer’s directions before using and know your spa’s gallonage for proper chemical treatment.

  2. Do not fill with water that exceeds 104oF.  This may cause damage to the finish or equipment.  After proper installation, fill spa to the recommended depth.

  3. Open all valves for proper water flow.  Inspect all plumbing and equipment for leaks.  Improper installation, use, or chemical treatment can result in heater failure and will void warranty.

  4. Keep the heater thermostat at a constant setting, increasing or reducing slightly until ideal temperature has been reached, but never over 104oF.

  5. Check and adjust water conditions.  You must maintain proper chemical balance to ensure safe sanitary conditions and to prevent your spa from becoming a breeding place for bacteria. How you can do this:

    • A. Test the pH every Monday, Wednesday, and Friday and maintain pH between 7.2 and 7.6. If the pH is above 7.6 use Leisure Time Spa Down or if the pH is below 7.2, use Leisure Time Spa Up.  Improper pH can damage spa finish, equipment, chlorine loss, and cause eye irritation.  Use dosage according to manufacturer’s label.

      1. If the pH level is too high, the water will become scale forming. This can shorten the life of your equipment and cause you to use more sanitizer than you otherwise would.
      2. If the pH level is too low, the water will become acidic. This can prevent your sanitizer from working as well as it should, which will allow harmful contaminants to remain in the water.
      3. Calcium hardness plays a major part in the pH level. If the levels are too high, scaling may occur, as well as buildup that is hard to remove and can irritate your skin and even eyes by soaking in it. If they’re too low, not only can problems with your plumbing and pipes occur, but also the water may begin to feel slimy. This slimy feeling can also get on your skin and remain even after you get out of your hot tub or spa.

    • B. Test the Alkalinity every Monday, Wednesday, and Friday and maintain between 80 ppm to 120 ppm.  If alkalinity is above 120 ppm use Leisure Time Spa Down, or Swimway pH Minus. If alkalinity is below 80 ppm, use Leisure Time Spa Up or Swimway pH Up. Use dosage according to manufacturer’s label.

      1. Maintaining alkalinity works as a buffer to keep the pH levels of your spa from fluctuating rapidly. Poor alkalinity levels can affect not only the appearance of your hot tub, but also your skin.
      2. Low alkalinity can corrode metal parts, erode the surface of your hot tub, and stop the water from balancing chemicals that prevent algae. High alkalinity can cause extremely high pH levels that are difficult to lower, as well as causing scale.

    • C. Test Chlorine/Bromine every Monday, Wednesday, and Friday to maintain proper sanitizer level.  Adjust if necessary using Leisure Time Spa 56 Chlorine/Brominating Disinfectant. It’s recommended in Endorol spas to use a chlorine sanitizer.  Chlorine levels should be maintained at 3 ppm and bromine at 3 ppm (0.5 ppm and ozone residual when using the Spa Mineral Purifier).  Typically two or three bathers in an average spa with 103o temperature will consume all the chlorine or bromine sanitizer in about twenty minutes.  Prolonged or heavy use may require additional chlorine or bromine to maintain safe sanitary conditions.

      1. How does chlorine work to sanitize your pool? The chlorine combines with bacteria in the water molecularly to kill them. Bromine, on the other hand, is used because it is more stable in warm temperatures. Bromine is also better for those with sensitive skin. Although bromine produces less of a chemical odor than chlorine, it is harder to wash away the chemical smell from your skin after bathing in a bromine pool or spa.

    • D. On Friday, and after each water change, shock water with Leisure Time Renew, Swimway non-chlorine shock, or a similar product. If using an Ozone system you may also use Leisure Time Renew Tabs.

      1. If you wait over a week between testing your water, it may be a good idea to shock it. This can be done using oxidizer to remove contaminants. If you use an oxidizer, do not cover your spa for at least 20 minutes to allow the gases that will be emitted to escape.

    • E. On Wednesday, use Leisure Time Spa Enzyme, Natural Chemistry Spa Perfect or Swimway Natural Enzyme or a natural enzyme formula to naturally biodegrade the organics that enter the spa, like body oils or cosmetics.  This will eliminate water line rings and act as a continuous filter cleaner, eliminating periodic soaking with chemicals.  

      Note:  Improper pH levels will cause early corrosion to your heating element and power pack, which is not covered under any manufacturer’s warranty.  If using Silver Ion Purifier or a Nature 2 Purifier, refer to Spa Owners Manual for specific instructions on chemical care and cartridge replacement.

  6. Drain your spa once every 3-4 months depending on its size, location and the frequency of use.  To remove stains, use baking soda on a non-scratch pad and scale on the spa finish. Use an automotive rubbing compound for very stubborn stains.

    • Locate the main drain valve and remove the cap. Attach a garden hose and open the valve. The spa and plumbing lines will drain by gravitational flow. Although the amount of time it takes to drain your spa varies due to unit size, this process should take approximately an hour.
    • Using a wet/dry vacuum is a quick way to drain your hot tub. Take a long vacuum hose and insert one end into your spa, connecting the other end to the vac. Turn on the vac for only a few seconds - just long enough to get a flow moving. Turn off the vacuum and remove the hose so that the water flows out. This is another method to remove any remaining water that does not require a submersible pump.
    • After removing stains from the interior of your spa, you should use a special cleaner on the surface. Spray the cleaner and use a clean cloth or paper towel to wipe clean.
    • It’s important to wax the interior surface of your spa to keep it in good shape. Remember, always thoroughly clean the surface of the spa before you wax it. Waxing will protect the surface of your spa but won’t affect the chemicals that you must add in order to maintain water quality.

  7. Clean filter and cartridge periodically and according to manufacturer’s instructions.  To service the filter, turn off the power, remove the lid, remove the filter cartridge, and wash out with water.  Use a quality non-sudsing detergent such as Leisure Time Filter Clean or Swimway Filter Clean and rinse thoroughly.  Reinstall filter and turn the unit back on. Keep a spare cartridge so that you can deliver a good cleaning and drying.

    • To clean the filter cartridge, you may spray it down in order to remove larger items, such as leaves. To more effectively clean your filter, use cleaner specifically made for cleaning filter cartridges, such as Spa Perfect or cleaner tablets.
    • If your filter is over a year old, it’s best to throw it away and use a new filter when opening your hot tub in the spring. For more information about filter cartridges, refer to our spa parts tips blog post.