How Often You Should Change Your Hot Tub Water?

Written for RotoSpa Birmingham. Published here.

Photo: Alan Levine/Flickr/Creative Commons (https://creativecommons.org/licenses/by-sa/2.0/)

Owning a hot tub isn’t set-it-and-forget-it in terms of maintenance. Keeping the water clean and safe is a big part of your hot tub routine, especially if you want to ensure your spa works for a long time. This shouldn’t come as a surprise since it is the primary element needed to have a good time in the spa.

How you manage the water’s hygiene levels will determine how long you can enjoy the spa. Spa chemicals and sanitisers are an essential part of your water care regime. We’ve already explained how to monitor pH levels and incorporate chlorine into your hot tub hygiene cycle.

Housekeeping rules

While some maintenance practices might vary from spa to spa, there are a few basic rules that all owners must follow. 

When possible, get spa users to wash down before entering the pool. Don’t drink in the pool (except for water) to minimise spills, and avoid wearing artificial tan.

It is recommended that you change the water at least every three months. This is required even if you’re diligent about water care. Do you want to sit in months-old water?

Clean the inline filter and wipe down the spa cover and cabinet every week. 

Don’t forget to regularly check the water’s pH levels. Earlier on, we mentioned using chlorine in your water care regime. Part of that practice involves adding chemicals that can impact the water’s acidity levels. Chlorine works best as a sanitsation agent when the water’s pH levels hover between 7 and 8; the pH scale goes from 0 to 14 with 7 being neutral.

Individual factors for different hot tubs

Given how different hot tubs can be, it should be no surprise that water care practices will differ. There are a few elements to keep in mind when planning out your maintenance schedule. 

• Total Dissolved Solids (TDS)

As the term suggests, total dissolved solids refer to contaminants left behind in the water after use. You might think you’re squeaky clean, but each time you enter the hot tub you’re leaving behind invisible particles that affect the water’s quality. In fact, if total dissolved solids build up for too long then they will eventually stop the sanitiser chemicals from mixing with the water. That just leads to dirtier water which could gradually become swamp-like, with scale deposits.

Unfortunately, chlorine doesn’t work against total dissolved solids. Sweat, shampoo, sunscreen, perfume—these are just some of the things that contribute to TDS. They are unavoidable but that doesn’t mean they have to be part of the water indefinitely. The easiest way to avoid excessive build-up of total dissolved solids is to have a quick shower before entering the spa, ensuring you remove all traces of soap too.

• Foamy water

No one likes foam in a spa. There are many substances that contribute to the creation of foam, including total dissolved solids and cleaning chemicals. Unbalanced pH levels and high volumes of TDS in the water can manifest as foam on the surface and ruin the hot tub experience. Also, remember to keep your body as free of external chemicals and substances as possible.

Those looking for a quick fix can try certain solutions that are specifically created to address the problem of foamy water. Depending on what brand you buy, you add between 20-40ml of the solution over the foam and watch it get to work. You could also try adding more chlorine than normal to clear up the water== just check afterwards that it isn’t too strong and potentially harmful.

• Bather load

Bather load is the number of people that use your spa and how often they use it. It’s pretty simple mathematics—when the bathers and frequency of use is higher, you change the water more often. Considering everything we’ve talked about so far, especially total dissolved solids, it’s easy to see why more people equals a - higher rate of freshwater supply. 

• Water volume

The size of your hot tub will also play a role in deciding when to change the water. Smaller tubs require freshwater more often because there is less water circulating. Our two to three person spas hold about 500-550 litres of water, the four to five person models hold 800 litres, while the five to six person spas hold 1000-1050 litres. 

If you’d rather not worry about all this, give us a call. We’ve got a number of spa packages that will maintain your hot tub in perfect condition so that all you have to worry about is enjoying the water.