How To Start A Hot Tub Or Spa (And Get It Running Properly)



Over time, no matter how much sanitizer is in the tub, the water becomes overloaded with pollutants and total dissolved solids (TDS).

This makes the water unsafe to bathe in, and at that point, you’ll have to drain the tub and start over.

If you’ve never done it before, you’ll learn it’s quite easy to do, and you won’t have to pay a professional to stop by and care for your tub.

Drain And Scrub (Cleaning)

Note: If you have a brand new hot tub you don’t need to do this part. Just keep everything turned off and skip to the next section on filling and balancing.

When starting over, you’ll need to get the tub sparkling clean once again.

What you’ll need for this part:

  • Submersible pump (optional)
  • Garden hose with nozzle
  • Non-abrasive sponge
  • Spa cleaning product

Step 1. Turn Everything Off

Start by cutting power to the tub.

For some, this can be as simple as unplugging it from the wall’s power outlet. Other models may require you turn off the breaker switch that it runs on.

In any case, you want to make sure there is no power running to the tub, as you’ll be moving large amounts of water out of it, and water and electricity do not mix. Safety first!

Step 2. Drain The Hot Tub

With the power off, the next step will be to drain the water from the tub.

There are two ways of doing this.

The first method is a slower process (takes about an hour or two), but only requires a garden hose. The tub will have a drain at the base of its exterior. Remove the drain plug, attach the hose to the port, and let the water drain out. 

Make sure you have the hose positioned to an area where it’s safe to send waste water. This usually is into a sewer or storm drain, but consult your city’s by-laws so you don’t end up with a fine.

The second method is faster (15 to 30 minutes), but it requires a submersible pump. The garden hose attaches to the pump, which is then placed into the hot tub. When you turn on the pump, water is sent from the tub, out through the hose. 

While there’s a bit more involved with method #2, a lot of owners invest in a cheap submersible pump to save time. 

Note: Don’t run a submersible pump without water in the tub. Many of these pumps come with an auto shut off sensor, but if it doesn’t, you may end up with a damaged pump.

Step 3. Brush Down And Scrub

If you want to get a headstart, you can begin brushing it down while the water is still draining. This will loosen any debris that may be stuck on the tub’s walls and seats so it can be expelled during the drain.

Once the tub is drained, mix spa cleaning solution with warm water in a bucket. Consult the cleaner’s instructions for the proper dosage, as products vary.

Dip a large, soft sponge into the bucket and scrub down the tub. It’s important that the sponge be non-abrasive, so it doesn’t scratch up the shell’s finish.

Get into every nook and cranny, scrubbing down the seats, the drains, skimmer, and jets. You may also need to use a little bit of elbow grease at the waterline, as it’s prone to scum buildup.

Step 4. Rinse And Final Drain

Once you feel the tub has been given a good scrub, rinse it to wash away the cleaning solution. You’ll need to be thorough in your rinse, as any remnants of the cleaning product in the tub may make it hard to balance your water.

A final drain will also have to be done. You can use either draining method for it but the important thing is that you flush out all the water from the tub.

If there’s any debris (ie. leaves, dirt) left over on the bottom of the tub, you can use a Shop-Vac to suck it up, or remove it by hand with a towel.

Step 5. Remove And Clean Filter

The last step to cleaning out the tub will be removing and cleaning the cartridge filter. In some spas this is located in the skimmer, while others use a dedicated cartridge filter located in the equipment chain.

Remove the cartridge from its housing and inspect it for damage. If it’s compromised in any way (tears, cracks), toss it away and replace it. A broken cartridge filter is an ineffective filter.

If it’s still in good shape, use your hose to spray it down, rinsing it of debris that has built up between the pleats.

Aim your nozzle down at a 45 degree angle so the water pressure doesn’t damage the filter media, while simultaneously pushing debris toward the ground.

Fill And Balance (Chemistry)

You’ve prepped the tub by cleaning it out after draining it. Now it’s time to put water back in and add the startup chemicals. 

We should mention that if you want to relocate the tub, now’s the time to do it. Once a tub is filled with water, it’s virtually impossible to move.

What you’ll need for this part:

  • A screwdriver
  • A garden hose with pre-filter
  • Sequestering agent
  • Chemicals to balance the water

Step 1. Check Your Connections

Start by opening the side panelling so you have access to the spa pack. You may need to use your screwdriver to remove these panels.

Look over all the equipment connections, making sure everything is tight and secure. The last thing you want is a loose union joint in your equipment chain that causes a leak while you’re filling/running the tub.

Step 2. Fill With Hose And Pre-Filter

The hot tub can be filled up with your home’s water source, which will likely be a hose attached to an outdoor spigot.

We highly recommend investing in a pre-filter that attaches to the hose. This will get rid of suspended solids and heavy metals that may be present in your water source. 

Open the tub’s filter well to remove the cartridge filter. Then, place the hose (hopefully with the attached pre-filter) in the well so fresh water can circulate through the plumbing and start filling the tub.

Once the spa’s foot well is filled, add in a sequestering agent (consult the bottle for proper dosage). This agent will help combat any suspended minerals still present in the water.

Identify the “minimum safe water level” line near the top of the tub. This is the level you should fill the tub to. While it may look too low, the water level will rise with people in it.

Step 3. Turn Everything On

With the tub filled up, you can turn off the hose and remove it from the filter well. Replace it with the cartridge filter you took out in the previous step.

Now it’s time to turn the tub on. It’s best to have an electrician hook it up to a dedicated breaker so it doesn’t overload your electrical grid. Once the tub has power, turn it on.

It will then enter “Priming Mode”, where you’ll manually activate each of the tub’s pumps before the heating cycle begins. If it doesn’t, check the control panel for this option.

When you cycle the pumps in “Priming Mode”, it purges (or “primes”) them of any air that may be in the plumbing. A few minutes after you prime the pumps, the heat cycle will automatically start.

Double check the connections again to make sure nothing is leaking. If everything looks good to go, you can reattach the side panelling to the tub.

Step 4. Test The Water Chemistry

Let the tub run and circulate the water for about 30 minutes. This allows the sequestering agent time to fully disperse in the water.

Now you’re ready to test the water and see where it’s current water chemistry stands.

Water testing can be done with test strips, a liquid testing kit, or a digital testing meter. Strips are the most convenient, but a digital meter will be the most accurate.

In spas, the levels you need to test for are pH, total alkalinity (TA), calcium hardness (CH), and your sanitizer – either chlorine or bromine.

Step 5. Add The Necessary Chemicals

Once you’ve completed your test, you can add in the appropriate chemicals needed to balance the water to a neutral state.

You’ll need to balance the ph, TA, and CH first.

The ideal levels of these should be:

  • pH between 7.4 and 7.6 (raise with soda ash or baking soda, lower with muriatic acid or sodium bisulfate)
  • TA between 80 and 120 ppm (raise with baking soda or Alkalinity Increaser, lower with pH Decreaser)
  • CH between 175 and 250 ppm (raise with calcium chloride or calcium hypochlorite, lower by draining/diluting)

Once these levels are set, you can add in your chlorine or bromine sanitizer (or any alternative sanitizer)

These ideal levels should be:

Remember to add cyanuric acid to the hot tub to protect and prolong the life of chlorine if the tub is exposed to sunlight. With bromine, you can only use it in a tub that is indoors or shaded from the sun.

After you’ve added all the chemicals, let the tub circulate them for 30 minutes.

Step 6. Set The Temperature

Temperature can impact the chemistry so it’s important to set this to the desired level before final water testing. 

A hot tub usually hovers between 98°F and 102°F depending on your preference.

Anything above 104°F can be detrimental to both bathers and the tub itself. Scalding can occur and damage to the shell is also common if the tub is too hot. 

Many heaters are equipped with an automatic shut-off function for exactly this reason, so the water can’t get overly hot and do damage.

Step 7. Test (Again) And Adjust

Once the temperature is set and the pump has run long enough to disperse the chemicals, test the water one more time.

This is to ensure no levels spiked or dropped with the addition of heat.

If you do notice levels that are out of sorts, adjust them, and retest until the water chemistry is back in check.

How To Keep It Running Smoothly

Here are a few final tips when it comes to hot tub maintenance:

  • Test frequently. A hot tub is a smaller body of water than a swimming pool, which means that pollutants can quickly upset the water chemistry. You’ll need to stay on top of weekly testing, and it’s recommended to test even more frequently if the tub is used multiple times per week, or any time there’s a high number of bathers.
  • Use a hot tub cover. Attaching and removing a hot tub cover can be a bit of a pain, but the benefits it provides are worth the extra effort. A hot tub cover will help the tub retain heat so you won’t have to run your heater as much, saving your money on your electricity bill. Additionally, with a lid on the tub it keeps debris out, and you won’t lose water or chemicals through evaporation.
  • Swap the water every 3 months. At the 3-month mark, turnover your hot tub. There will simply be too many pollutants that accumulate in a 90 day timeframe for the chlorine or bromine to be effective against. Draining, cleaning, and refilling the tub every 3 months keeps the spa clean and free from contaminants that can cause water issues.
  • Use quality chemicals. Hot tubs are a luxury item, and you should only invest in one if you can afford the upkeep they require. At times, you may be tempted to skimp on the chemicals, opting for cheaper ones. This will always come back to bite you. The more expensive chemicals are priced that way because they’re higher quality and work more effectively, keeping your water clean and properly balanced.
  • Check your filter. The cartridge filter should be checked and cleaned every 2 to 3 weeks. This can be a simple hosing down to remove any built up debris like dirt and leaves, but every 60 to 90 days you should do a deep soak to remove all the grim on it. By inspecting it every few weeks, you’ll be able to replace it quickly if you notice it’s torn or broken, so the water won’t suffer from inadequate filtration.

Go Start Your Hot Tub!

There you have it – everything you need to know to start your hot tub.

Use this startup guide if you’re opening your spa for the first time, or anytime you’ve drained it to change out the water.

Categories: Hot Tub Care, Hot Tub Maintenance