Updated: November 2017
Spa and Hot Tub Maintenance and CareAdding a spa or hot tub to your home can be a real luxury, and an expensive a luxury. A good spa can cost $6,000-$15,000, while you can find low-end spas for $3000-$6000. Whatever you decide to buy, with that kind of investment it is important to keep your hot tub in top running condition. Caring for a hot tub is different than caring for a swimming pool. While a pool has 10s of thousands of gallons of water in it, a spa has only 300-500 gallons. And unlike a bathtub that you drain after each use, your hot tub holds the same water in it day after, bather after hot sweaty bather. As we'll discuss in this guide, keeping your hot tub clean takes work, but once you get the hang of it, most people can perform their spa maintenance in just 10-15 minutes per week. Read below for details on pH balance, alkalinity levels, chlorine and sanitizers, and oxidizers.
Spa Sanitizers - Chlorine, Bromine, OzoneOne of the most important tools in keeping your hot tub clean is using the proper amount of sanitizer. Just like in a pool, sanitizer in a spa (like chlorine) disinfects the water and kills bacteria and microbes that want to live in the water. Since your hot tub is smaller than a pool, you of course use a lower concentration of chlorine in your hot tub. Apart from chlorine, there are also a few other popular spa sanitizing chemicals and systems. Bromine is similar to chlorine but is less harsh on the skin and does not smell as strongly. In fact, the bromine tablets you can put in your spa are made of chlorine and sodium bromide. Most bromine solutions use a floating "brominator" that allows the bromine tablet to slowly dissolve into the water over time. Another popular sanitizer is ozone from an ozonator. An ozonator is a special piece of equipment inside the motor compartment of your hot tub that produces ozone (O3). Ozone is released into the spa water to oxidize and destroy bacteria and other contaminants (viruses, algae, yeast, cologne, sun tan lotion, saliva, urine, etc). Ozone is pretty short lived (it only lasts about 15 minutes before converting back to regular O2 oxygen) and cannot do all the sanitizing work in your spa, so some lighter use of bromine is still required to maintain the health of your water. There are UV ozonators and solid state corona discharge (CD) ozonators - the CD types use a lot less energy and are hardier. If your tub did not come with an ozonator, they are pretty simple to add on as an aftermarket device costing about $100-$150 (check out SpaDepot.com). Amazon also carries most hot tub and spa chemicals, making shopping online easy.
Most newer, higher end hot tubs come with ozonators -- be sure to ask your spa reseller to include one in your spa. They help reduce (but not REMOVE) your need for chlorine and other caustic sanitizing chemicals, which is a good thing for everyone. So those are your basic choices when it comes to keeping nasty creatures out of your spa - hopefully get an ozonator, and then decide if you want to use chlorine or bromine to maintain a good sanitizer level in your water (we prefer bromine tabs).
Cleaning your Hot Tub - Balancing Your WaterHow do I balance my spa water? Hot tubs tend to accumulate everything found on people's body, from perspiration to deodorants to soaps and shampoos to body oils and other natural organic materials. Since you don't drain the tub after each use, you have to find a way to keep the water clean and to keep bacteria and other yucky stuff from growing in your warm water. To keep your hot tub water clean, you have to regularly test it, measure the levels of various chemicals, and then add additional chemicals as needed to keep your water healthy. This is called balancing your water. The first item at hand is the pH level. For those of you that have forgotten your high school chemistry, pH measures the acidity of the water by measuring the balance of positive hydrogen ions (H+). A neutral solution has a pH of 7, while lower values are considered acidic and higher values are considered basic. Your goal for your hot tub is to have the pH be in a range just above 7 -- about 7.2 - 7.8. If your water is too acidic, it can corrode your plumbing and damage seals (and your skin!). If the pH is too high, you can get alkaline scaling and build up in your tub and the plumbing equipment. So keep your water within the recommended guidelines. Total Alkalinity (TA) is the other important measure to keep an eye on. Your goal for TA is 80-120 PPM. TA measures the waters ability to resist pH changes by neutralizing acid, acting as a buffer for your spa water. If your TA is high, it is hard to change the pH of your water. This is good if you have your water at the right pH level, not so good if it is not. You can increase your TA by adding simple sodium bicarbonate to your water (baking soda - check out this site for details). Always add small amounts of chemicals at a time, then retest. It is tough to remove excess chemicals from your water, but easy to add a little more. You can also use commercial products like Leisure Time Spa Up or Spa Down to change the pH and TA levels in your hot tub. Soda ash can be added to increase pH while not affecting TA.
To test your water balance in your spa, you will use little test strips that you buy from Amazon or your spa supply shop. They look like little strips of plastics with colored squares glued to them. The 3 or 4 squares on them each test for different chemical conditions - alkalinity, pH, sanitizer PPM, and Calcium levels in the water. You swivel the strip around in the water 3 or 4 times, about 6 inches below the surface, then lift the strip up (do NOT shake the water off it) and compare it to the color chart on the container it came it. Match up the color on the strip to the provided color scales to get your readings for pH, TA, etc. If you find your water is not in the balanced levels, then you need to adjust your water with various chemicals.
After you keep your water clean, you need to drain and refill your water every 3-4 months. No one wants to sit in that chemical bath for too long! You also need to clean your filter monthly and replace it annually. A dirty worn-out filter leaves you with dirty worn-out water -- not something you want.