Spa Water Chemistry
The importance of learning how to maintain spa water can not be understated. In addition to protecting your investment, knowing how to keep your spa clean and clear is sure to increase your enjoyment and decrease your time spent fighting water quality issues. A spa that contains well balanced water will outlast a poorly maintained spa by many years.
There is much confusion about water chemistry in spas and a great deal of this comes from people who have learned water chemistry from someone who does not understand water chemistry themselves.
Spa Water Balancing Explained
The point is to gain an understanding of the bigger picture of maintaining spa water. If you attempt to memorize a few key aspects of water balancing then you will never fully grasp how and why your water gets cloudy or turns green or smells bad.It is not a matter of putting some shock in every now and again. It is a matter of developing a balance between multiple variables creating a state of equilibrium in a sterile environment while maintaining an acidity level tolerable for humans.
Chlorine Allergies
As a pool and spa professional I often hear from clients that they are allergic to chlorine. Though possible, this is almost never true. The amount of chlorine that every person is exposed to in our drinking water pretty much prevents this allergy from happening.The red eyes and itchy skin that can be a part of spa use is actually caused by poorly maintained pH levels in the water and has nothing to do with the level of sanitizer. Lack of sanitizer is a major problem that can cause reactions more severe than dry skin and red eyes.
What Is Sanitizer
The sanitizer is the chlorine or bromine in the water, which acts as a disinfectant killing bacteria and preventing the growth of lesser bacteria into stronger and more dangerous bacteria.Both bromine and chlorine are approved chemical sanitizers for use in North America. Bromine has a 27% chlorine concentration so both are in fact chlorine based sanitizers.
How To Measure Sanitizer
At a range of 1-5 parts per million, or ppm for short, these sanitizers will prevent bacteria growth in the tub. Free chlorine is measured as the amount of sanitizer available in the water available to kill bacteria where the total chlorine level measured in the water accounts for both the free chlorine as well as the combined chlorine which is the chloromines and dead bacteria left over after the free chlorine has done its job.The longer you have the same water in your spa, the more chloromines that build up, which is why you must periodically drain the spa and refill with fresh water.
Potential Of Hydrogen
Potential of hydrogen, or pH, is the measure of the balance between acids and bases in the water. It is measured on a scale of one to fourteen with once being very acidic and fourteen being very basic. The range of 7.2 to 7.8 is the ideal range for spa water as this will cause the least reaction with people.The pH of the human eye is 7.4. The further away from this number that your pH level is in the spa, the greater the likelihood and greater the severity of red eyes and itchy skin.
Does Chlorine Influence pH?
Adding chlorine to your water as a sanitizer will drive up the pH level over time as the chlorine has a pH in the range of 11. This is why you need to monitor your pH levels as they will change over time and chlorine can only be free, or active, within a certain range of pH.Bromine remains active in fluctuating pH conditions where chlorine does not and this is one of the benefits of using the more expensive bromine over chlorine as the sanitizer in spa water.
What Is Total Alkalinity?
Total alkalinity is the measure of metals and alkaline (read: basic) material in the water, and is a direct indication of the waters ability to resist changes in pH. Measured as 70-180 ppm in a regular spa or 70-120 ppm in a salt water spa the total alkalinity of the water helps to prevent fluctuations in pH.Calcium Hardness Levels
Calcium hardness is the measure of calcium and magnesium in the water. Measured as 125-400 ppm in a regular spa or 70 minimum in a salt water spa, the calcium hardness indicates the potential for your hot tub to develop scale. At higher ppm concentrations scale will begin to form on the surface of the tub as well as inside jets, pumps, filters, heaters and plumbing lines. This scale has a pH of 1-2 and is very corrosive to plastics. It feels much like sandpaper and can void the warranty on spa components such as the heating element with most manufacturers.Using a stain and scale water conditioner, or mineral salts, can help to soften the water and reduce calcium hardness. Be sure to never use water from a water softener to fill your hot tub. Soft water has a calcium hardness of zero so scale is not the problem, the problem is that the water is so soft that even trace amounts of shampoo or laundry detergent can cause huge and long lasting bubbles in the spa.
What Can Happen If Spa Water Is Not Balanced
The importance of water quality can not be understated. Keeping the water clean and safe is not recommended – it is an absolute requirement of owning a hot tub. A spa with poorly maintained water is an ideal environment for bacteria to grow.In 1999 at a fair in the Netherlands a hot tub killed 20 people and caused some 240 people to become sick. This was not limited to bathers but also just people who were only exposed to the vapour created from the jets and swirling water. Not a rare occurrence, the legionella bacteria can develop in hot tubs as well as many other forms of harmful bacteria. Water quality maintenance is critical to the safe use and enjoyment of a spa.
99% Of Spa Bacteria Is In The Plumbing Lines
Periodic flushing and draining of the hot tub is required in order to maintain water quality. The vast majority of bacteria in a spa exists in the plumbing lines as opposed to on the shell or suspended in the water itself. Biofilm feeds bacteria and must be removed before you drain the water from your tub to limit the contamination of the fresh water with established bacteria.Use a hot tub flush product and thoroughly run the system of your hot tub to ensure all lines have been cleaned before you drain your tub. This will dramatically reduce the amount of bacteria in the spa.
Eliminate Biofilm To Eliminate Bacteria
Using a mineral solution to remove and reduce biofilm is strongly recommended. This is a relatively new technology for spa treatment that essentially removes the biofilms, which feed and protect bacteria, and prevent biofilms from forming again by adding a protective layer to the surfaces of the spa and plumbing lines.There are a few different products available depending on where you are located but ask your spa supply store for a product that is specifically designed to reduce biofilms. This can reduce the total amount of bacteria in your spa drastically so that the sanitizer has less bacteria to kill.
Spa water with reduced biofilm will be much easier to maintain, will not smell foul or of chlorine, will resist fluctuations in pH and total alkalinity and can be maintained with as little as .5ppm of sanitizer.
Water & Filter Changing
Change your filter often, bring your water into your local spa dealer for testing and flush drain and fill your hot tub every three months. Some people can get as long as six or nine months out of the spa water however this is not recommended for novice spa owners as the risks far outweigh any potential benefits.
Proceed to the section that deals with Spa Covers to learn how much money a good quality spa cover can save you.