The Right Way to Fill a Hot Tub – Tips for a Perfect Start




Filling a hot tub may seem simple, but there’s more to it than letting a hose run into it. To maintain the right balance of chemicals and ensure the longevity of your hot tub, it’s important to follow a proper procedure. This article will guide you through the steps to fill a hot tub, including essential preparation, water treatment, and common troubleshooting tips.

Before starting the process, gathering all the necessary tools and materials, such as a hose with a pre-filter, a sequestering agent, and the appropriate chemicals, is important. Additionally, it’s a good idea to familiarize yourself with the user manual of your hot tub since manufacturers may have specific instructions or recommendations for their models.

With everything prepped and ready to go, you can begin filling your hot tub safely and effectively.

Remember that filling a hot tub might take longer than expected, and it is crucial not to rush the process to ensure a properly balanced and healthy experience.

How to Fill a Hot Tub

Key Takeaways

  • Prepare the necessary tools and materials, and read your hot tub’s user manual.
  • Follow the appropriate steps to fill your hot tub and treat the water.
  • Use the filter housing as the fill point to prevent air lock.

Preparation for Filling Your Hot Tub

Before filling your hot tub, making the necessary preparations is essential. This section will cover the two key aspects that require your attention: choosing the right water source and cleaning before filling.

Choosing the Right Water Source

When filling your hot tub, selecting the appropriate water source is crucial. Typically, a garden hose serves as the most common option.

However, it is highly recommended to attach a pre-filter to your hose. This step will help remove any minerals from your source water, making it easier to balance chemicals later.

Some popular pre-filters include activated carbon or sediment filters that effectively filter out these impurities.

Cleaning Before Filling

Proper hot tub cleaning before filling is essential to ensure longevity and maintain cleanliness. Follow these steps for a smooth and efficient cleaning process:

  1. Remove debris: Check for any debris, such as leaves or dirt, and remove them from the hot tub surfaces.
  2. Sanitize the surfaces: Use a hot tub cleaner product to clean and sanitize the hot tub surfaces. Ensure you follow the manufacturer’s instructions regarding the cleaner’s application.
  3. Clean the filter housing: Remove the filter closest to your hot tub’s control panel. This area is where you will place your hose with the pre-filter attached during the filling process. Cleaning the filter housing will help clear any build-up of air when water flows through the pipework.

These preparation steps will set you up for success as you begin filling your hot tub. With the right water source and a clean tub, you can confidently move forward and enjoy your refreshed hot tub experience.

Steps to Fill Your Hot Tub

Filling your hot tub correctly is essential to ensure optimal performance and longevity. Follow these steps to fill your hot tub efficiently and safely.

Connecting the Hose

  1. Attach a pre-filter: Connect a pre-filter to your garden hose to remove minerals from the source water, making it easier to balance the chemicals.
    Garden Hose Filter for Filling Pool,Garden Hose Filter for Filling Hot Tub/Spa, Greatly Reduces Sediment, Chlorine, Heavy Metals and Odors, Standard 3/4" Garden Hose Thread, Up to 8,000 Gallons
  2. Position the hose: Remove the filter closest to your hot tub’s control panel, and place the hose with the pre-filter attached in this area. Filling through the filter housing helps prevent airlocks in the plumbing system.

Monitor Water Levels

  1. Turn on the water: Begin filling your hot tub. Keep an eye on the water level – depending on pressure, it may take 15 to 1 hour to fill.
  2. Add a sequestering agent: When the water level reaches the footwell, add a sequestering agent to remove any remaining suspended minerals. Ensure the water doesn’t reach the maximum level.
  3. Water temperature: Fill your hot tub with cold or lukewarm water, as hot water can damage the heater sensors. Read my post – How high should you fill a hot tub.

Checking for Leaks during Filling

  1. Inspect for leaks: As you fill your hot tub, periodically check for leaks around the pump fittings and plumbing connections. Address any issues immediately to prevent potential water damage.
  2. Purge air from the plumbing: Once your hot tub is filled, you may need to purge any trapped air from the plumbing system. Refer to your hot tub manufacturer’s guidelines to perform this step correctly.
  3. Turn on the hot tub: After filling and purging the air, power on your hot tub and allow it to heat up and start circulating. This is an ideal time to check and balance the chemicals in your water.

By following these steps, your hot tub will be filled correctly, allowing you to enjoy a relaxing and enjoyable experience.

Water Treatment After Filling

I recommend buying a hot tub starter kit containing everything you need to get your hot tub up and running.

A good choice, available on Amazon, is the Hot Tub Things Chlorine Starter Kit – which includes chlorine granules, test strips, alkalinity up & down, clarifier, metal out, & oxidizer.

Hot Tub Things Chlorine Starter Kit - Spa Maintenance, Eliminate Cloudy Water, Hot Tub, Jacuzzis, Includes Chlorine Granules, Test Strips, Alkalinity Up & Down, Clarifier, Metal Out, & Oxidizer

Balancing Chemical Levels

After filling your hot tub, it’s essential to treat the water to ensure a safe and enjoyable spa experience.

Test the water:

  • Use test strips or a test kit to determine pH, alkalinity, and sanitizer levels.
  • Ideal pH: 7.2 to 7.6
  • Ideal total alkalinity: 80 to 120 parts per million (ppm)

Recommended Test Strips

AquaChek 7-Way Pool and Spa Test Strips - Silver Pool Test Strips For pH, Total Chlorine, Free Chlorine, Bromine, Alkalinity, Total Hardness, and Cyanuric Acid - Water Quality Testing Kit (100 Strips)

Aquachek 7-way test strips

I use these test strips that can tell you the total chlorine/bromine, free chlorine, pH, total alkalinity, CYA and hardness levels.

Adjust as necessary:

  • To raise pH, add soda ash; to lower it, add muriatic acid.
  • For alkalinity, add baking soda to increase or pH decrease to reduce.

Add sanitizer:

  • Chlorine or bromine is commonly used.
  • Follow the manufacturer’s guidelines for the correct amount.
ChemicalPurposeIdeal Level
Chlorine/BromineSanitizationVaries by product
pH Increasers/ReducerspH Level Adjustment7.2-7.6
Alkalinity IncreaserStabilize pH100-120 ppm
Shock TreatmentRemove Contaminants/BacteriaAs directed

Water Circulation and Heating

Proper water circulation and heating also play a crucial role in maintaining water quality. When you’ve treated the water, it’s time to turn on the hot tub’s circulation system to ensure the distribution of chemicals and keep the water clean. Ensure your hot tub’s filter is clean and functioning correctly for optimal water circulation.

In addition, the ideal water temperature for a hot tub is usually between 100°F and 104°F (38°C and 40°C). Remember to allow enough time for the water to heat to the desired temperature before use.

Depending on your hot tub’s capacity and heater size, heating may take several hours. When I bought my first hot tub in the winter, the faucet water was so cold that it took 18 hours to heat.

Keeping the cover on your hot tub while heating can speed up the process and retain the heat more efficiently.

These steps will effectively treat and maintain the water in your hot tub, ensuring a comfortable and enjoyable experience.

Time Considerations

Average Duration for Filling

Filling a hot tub typically takes anywhere from 15 minutes to 1 hour, depending on the size of your hot tub and the water pressure your source provides.

You could use a 5-gallon bucket, a timer, and your garden hose to get a rough estimate of filling time. Time how long it takes to fill the bucket and then calculate how many buckets are needed to fill your hot tub.

This will give you a rough idea of the total time required to fill the spa. But at the end of the day, it will take as long as it takes.

Factors Affecting Filling Time

Several factors can affect the time it takes to fill your hot tub:

  1. Hot tub size: Larger hot tubs require more water and will take longer to fill. Smaller hot tubs will fill more quickly.
  2. Water pressure: The pressure of your water source can greatly impact filling time. Higher water pressure will fill your hot tub faster, whereas lower pressure will take longer.
  3. Pre-filtering: Using a pre-filter on your garden hose can help remove minerals and contaminants from the water but may slightly increase the filling time. However, it’s worth the extra time, as this will make it easier to balance the water’s chemistry.
  4. Jet placement: While filling your hot tub, ensure the water level remains above the jets and doesn’t rise too high, which could cause overflow. Follow the guide in your hot tub manual to identify the correct water level.

Monitor the water level as it fills and adjust the flow if necessary to ensure a smooth and efficient filling process.

Troubleshooting Common Issues

Handling Water Discoloration

In case you notice your hot tub water becoming discolored, follow these steps to address the issue:

  1. Check the water chemistry: Use a test kit to measure pH, alkalinity, and sanitizer levels. Ensure they are within the recommended range.
  2. Clean the filters: Rinse your filters monthly to maintain clear water flow. An instant filter cleaner spray breaks up oil and other stubborn buildup.
  3. Replace the water: If the discoloration persists after adjusting the water chemistry and cleaning the filters, it may be time to drain and refill your hot tub.

Remember, proper water maintenance plays a crucial role in preventing water discoloration.

Dealing with Air Lock

Air lock can occur when air gets trapped in your hot tub’s plumbing system, causing water flow and circulation issues. Follow these steps to resolve an air lock issue:

  1. Air bleed Plug: My hot tub, and some others, have a small plug located at the high point in the system that unscrews. With the pump running, you remove the plug to let air out, and then, as soon as the water comes out, the plug is replaced.
  2. Relieve pressure at the pump: Turn off the hot tub, loosen the pump’s fittings, and allow air to escape. Tighten the fittings once you no longer hear air escaping.
  3. Adjust jet settings: Try incrementally switching the jet speeds from low to high, slowly pushing the air out of the lines.
  4. Prevent future air lock: When filling your hot tub, place the hose in the skimmer/filter housing. This method allows air to escape while the tub fills, preventing air lock.
The Right Way to Fill a Hot Tub - Tips for a Perfect Start 1
The hot tub bleed plug on my hot tub

These techniques can easily resolve air lock issues, ensuring smooth water flow in your hot tub.

Frequently Asked Questions

What are the first steps before adding water to a new hot tub?

Before filling up your hot tub, ensure that the tub is clean and in proper working condition. Thoroughly clean the hot tub’s interior and ensure all components are in their correct positions. This preparation step is essential to keep your hot tub functioning correctly and maintain cleanliness.

Which chemicals are necessary when starting up a freshly filled hot tub?

Add a sequestering agent to the water once the level has filled the footwell. This agent will help remove any remaining suspended minerals that got through the pre-filter. Afterward, it’s essential to balance the water chemistry by testing and adjusting pH, alkalinity, and sanitizer levels according to the hot tub manufacturer’s recommendations.

Avoid filling the hot tub to the maximum level, as this may cause water to spill out when people enter the tub. Instead, maintain a sufficient water level to immerse the highest jets or reach the designated level indicated by the manufacturer. This will ensure efficient water flow and prevent overflow.

How much time is typically required to fill a hot tub?

The time to fill a hot tub depends on the water pressure and size. Generally, it takes around 15 to 1 hour to fill a hot tub under normal conditions. However, filling larger hot tubs or those with low water pressure may take longer.

Is it possible to fill my hot tub through the filter, and if so, how?

Filling through the filter compartment can help remove air from the plumbing system. Remove the filter, attach a pre-filter to your garden hose to screen out minerals and contaminants, and place the hose into the filter canister area to fill.

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