Hot tub maintenance & care – a beginner’s guide

Posted by Nick Clamp in Maintaining a Hot Tub Guides on 1st October 2019

Taking a regular dip in a quality hot tub can unlock the combined wellness benefits of a healthy mind and body. Numerous studies have proven a positive link between regular bathing in a hot tub and reduced stress, better sleep, weight management and enhanced social interaction with family members.

The health and lifestyle benefits of hot tub ownership are therefore firmly established, so here we look at one of the main practical questions that many new and prospective hot tub buyers ask – “How easy is it to look after a hot tub?”

The important thing to note before you read on, is that to the uninitiated, hot tub water care sounds a little daunting. Do not fear, all WhatSpa? Approved dealers are very well versed in providing initial and ongoing customer training to ensure that you are 100% confident in looking after the water in your fabulous new hot tub.

Hot tub water care shouldn’t take you more than 30 minutes a week once you’re up to speed, but here’s a detailed breakdown covering the essential elements of hot tub maintenance and care:

Commissioning your spa

Photo © Hot Tubs Hampshire

After your new hot tub is installed and all the electrics have been signed off, it should be filled up and fully tested to confirm that everything works as it should and it is operating safely.

Professional hot tub dealerships will have a standard procedure for commissioning that will ensure that by the time their installation staff leave, you’ll be fully trained not just on how to work your shiny new hot tub, but also that you are proficient in how to look after the water so that it is safe and crystal clear whenever you want to use it – morning, day or night.

Ongoing hot tub maintenance

Once your hot tub is up and running, has been commissioned properly, is ready for use and it is up to bather temperature (between 37oC and 38.5oC is a comfortable range for most people), here’s a breakdown of the water maintenance checks and balancing that you will need to undertake at regular intervals:

1. Daily Checks

On a day to day basis, you only have to ensure that there is adequate levels of sanitiser in the water (chlorine or bromine are the most recognised sanitisers on the market) and also that the pH of the water (its acidity or alkalinity) is balanced correctly.

This might sound daunting at first but it is quick and easy using test strips that are designed specifically for the residential hot tub market.

The ideal ranges are as follows:

  • pH = 7.2 – 7.6
  • Free Chlorine = 3 – 5mg/l (milligrams per litre)
  • Total Bromine = 4 – 6mg/l (milligrams per litre)

Note that you should use either chlorine or bromine so you will only be testing for the particular sanitiser that you are using.

pH control:

It is important to monitor for pH on a daily basis as both low and high pH values can be uncomfortable for bathers and can lead to skin or eye irritation. Low or high pH values can also hamper the efficiency of the sanitiser (especially chlorine) to control and kill potentially harmful bacteria and pathogens.

Low pH can be corrosive and lead to damage to spa equipment over time and high pH can be scale-forming leading to cloudy water and scale formation on heating elements and other spa surfaces.

Remember that the ideal pH range is between 7.2 and 7.6, so if the pH is lower than 7.2 use a pH increaser and conversely if the pH is above 7.6 use a pH reducer.

Sanitiser control:

The primary sanitiser (chlorine or bromine) is your main defence against harmful water-borne pathogens, so it is vital to test and adjust sanitiser levels as required on a daily basis.

Many spas now come equipped with built in sanitiser tablet dispensers to make this even easier, so keep an eye on the tablet dispenser to check that the tablets haven’t completely dissolved.

2. Weekly Checks

Photo © Merlin Pools

Turn on all the hydrotherapy pumps, open any topside air controls and ensure that any adjustable flow-control waterfalls or jets are turned back on. If the spa is producing visible foam at this stage, you can add a small quantity of spa foam suppressant until the foam dissipates. Then turn the air controls and waterfalls back off.

Visually check the water for clarity; if the water is cloudy, you can use a combination of fast-acting oxidisers and clarifiers that will help to clear the water again.

If you are in a hard water area, add a dose of Anti-Scale, which will keep any calcium in suspension in the water and prevent it from scaling up your heating element and other spa surfaces.

Check for Total Alkalinity (TA). Total Alkalinity is a measurement of the water’s ability to resist pH change. If TA is low, pH can easily fluctuate making it difficult to control and maintain the ideal level for the rest of the week. Ideally aim for a TA level of between 125 – 150mg/l but at least 80mg/l is desirable.

If there are any leaves, debris or grit in the footwell, use a skimmer net or spa vacuum to get the spa looking tip top again. Give the topside and waterline a quick wipe down with a damp cloth and a spa surface cleaning solution, then clip the spa cover back into place and you are golden for another week of hot tub fun and relaxation!

3. Monthly Checks

Photo © Villeroy & Boch

Remove the filters from the spa (for cleaning later) then thoroughly clean the inside of the spa surfaces with a damp cloth and a spa surface cleaner solution. Replace the filter with a clean replacement (always keep two sets of filters, so that one set can be cleaned whilst the other is in active use).

Do your final checks for pH and sanitiser levels and check that the set temperature of the spa is set to your ideal temperature, hose down and chemically clean your filters (using a spa filter cleaning solution), then leave them to dry thoroughly in readiness for putting back into use next month.

4. Quarterly Checks

If your hot tub is used three or four times per week, it is recommended that you drain down and refill the hot tub at least once every three of four months.

Before drain down:

Before you drain down the hot tub, we advise that you first ‘zap’ the water with a fast acting plumbing cleaner to remove any residue or greasy body oils from the inside of the plumbing system.

If the hot tub is equipped with headrests, remove them and thoroughly clean the headrests and the acrylic area behind them to remove any potential contaminants. Once dry, use a vinyl protectant such as 303 Protectant to give them surface protection and preserve their lifespan.

Once the hot tub is thoroughly cleaned and completely drained down, you can now start the refill process.

As the spa is refilling, add some fast acting chlorine or bromine granules to start the sanitisation process. Remember that you are aiming for Free Chlorine level of 2 – 5mg/l or a Total Bromine level of 3 – 6mg/l once the spa is refilled so don’t go overboard at this stage with your dosing.

After refill:

Once the spa is full, check and adjust pH to 7.2 – 7.6 and also check for Total Alkalinity (TA). If TA is low, pH can easily fluctuate making it difficult to control and maintain the ideal level for the rest of the week. Ideally aim for a TA level of between 125 – 150mg/l but at least 80mg/l is desirable.

If your spa is equipped with a hot tub cover made of vinyl, wash the vinyl with warm soapy water, leave it to dry then use 303 Protectant to protect it from UV damage from the sun. Again this will preserve its lifespan.

5. Yearly Checks

We recommend that you conduct an annual equipment service on your hot tub to ensure that it is fully operational and all of the equipment is working properly and to your safety standards. Particularly check that your secondary sanitisation equipment (ozonator or UV equipment) is working properly and that UV bulbs are replaced in line with your supplier’s recommendations.

Also replace your filters at least once a year as filter media degrades over time and will eventually provide inadequate filtration performance leading to cloudy water.

About the author

Nick Clamp

I am the Editor-in-Chief at WhatSpa? Media Group and my job is to keep you informed about the very latest hot tubs on the UK market... the best job in the world! When I'm not being deluged with press releases and hot tub brochures I enjoy keeping fit and participating in endurance events including triathlons and distance running.

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