Yes, You Do—Here’s Why


American Whirlpool Hot Tub

Lots of people aren’t sure about how often the water needs changing in their spa or they don’t want to take the time to do it because the water still looks clear. After all, you don’t need to drain a swimming pool, why do you need to drain a spa? Let us convince you…

Change Your Spa Water Every 3-4 Months, Here’s Why:
As you add chemicals they are adding to the saturation of the hot tub’s water.  It’s like the high school chemistry experiment where you add a tablespoon of sugar to a glass of water and it dissolves.  As you continue to add more tablespoons, they start to dissolve slower and slower until the sugar doesn’t dissolve and drops to the bottom of the glass.  That water is saturated. The same thing starts to happen as the hot tub’s water gets “older”.  The water will start to get hazy and you might even experience grit on the shell. You also might have a harder time keeping the water chemistry balanced and you might even notice a bit of a ‘funky’ smell.

A spa contains a much smaller amount of water than a pool—and the more people you add, the more “leave behinds” in a smaller volume of water.  One of the many benefits of using a hot tub is that you detoxify your body through sweating.  The sweat is removing deodorant, lotion, perfume, etc. which doesn’t dilute very well and can lead to foaming and/or cloudy water.

Temperature also plays a big part. Spas are kept very hot and this affects what you need to do to keep your water clean and clear.  As the hot water evaporates, it leaves behind any added solids: chemicals, bather waste, etc all adding to the saturation of the water.
As the hot tub water gets older and the Total Dissolved Solids (TDS) raises you will notice your filter may need to be cleaned more often.  The filter is trapping the partially dissolved solids that can reduce the energy efficiency of the hot tub’s heater.

Okay, Okay So How Can I Tell When to Change The Water?
Test your water:
You should be testing the water regularly anyhow. If the water stays in balance, you should be able to make the 3-4 month mark before you need to drain and change.  If you have consistently cloudy water, grit, or an odor develops, it’s time to drain the water.
Whenever you bring a water sample to Pettis Pools ask for a TDS test, it only takes a couple of seconds.

You can also use this formula:
Find out how much water is in your spa. (Roughly: 2-seater spa holds 200 gallons, 7ft x 7ft hot tub holds 300 gallons, 8ft X 8ft hot tub holds 400 gallons)
The next thing you need to know is the ‘bather load’ of your spa—how many people use it and how often.

The general rule of thumb when it comes to calculating how often to change the water in your hot tub is to divide the total number of gallons of your hot tub by 3, and then divide it again by the number of daily users. This formula will give you an approximation of the number of days that you can go between changing the water in your hot tub. For example, if you have a 480-gallon hot tub and have 3 average daily users, you should be changing the water in your hot tub approximately every 53 days.

This formula is not a hard and fast, set in stone rule when it comes to changing your hot tub water. There are some other things that you should look out for to keep your spa in optimal operating order throughout the year. If you notice that the water in your spa is cloudy and shocking it doesn’t seem to clear it, it’s time to drain and refill. If you are developing a lot of foam and the defoamer isn’t having an effect, it is also likely time to change the water. The most noticeable sign that it is time to change the water in your hot tub is if the water begins to smell. A foul smell is a sure sign that you are overdue for changing out the water.

While You’re At It
When you decide to drain your hot tub, take the time to give the plumbing and jets a thorough cleaning. A spa with clean plumbing gives you clearer, fresher water and better circulation. Add a flush product to the water before you drain and run the pumps on high speed for about 20 minutes. We stock everything you need. Just be aware, if your spa hasn’t been cleaned for a while this will probably flush a lot of dirt into your water that can be thrown out when you drain.

Give us a call or stop in with any questions you have about spa care. Pettis Pool & Patio’s staff is ready to help you all along the way.