How to Drain and Clean a Hot Tub
It’s a good idea to do a twice yearly drain and clean of your spa. If you are an avid user throughout the year, you might look at cleaning it three or four times a year.
Does the thought of the drain and clean leave you wondering just how to do it? Wonder no more. We’re going to look at how to drain and clean a hot tub easily and efficiently.
Why Change the Water?
Imagine that your hot tub is one big bath tub. You drain that water because it gets dirty and filled with body oils and dirt.
While you use chemicals in your spa to keep it clean, leaving the water in your hot tub all year long isn’t the best way to go. Even if it looks and feels clean, you probably have a buildup of chemicals that should be drained out on occasion. Draining your water also helps rid your spa of any chemical smell.
Purge Your Lines
Before draining your hot tub, you want to flush out your lines. Most of the bacteria in your spa lives inside the plumbing lines under a layer of a sticky tar like substance called biofilm.
This biofilm is a layer of mechanical protection that prevents the chemical sanitizers in your system from reaching the bacteria. Biofilm sticks to the surfaces of your hot tub that encounter water, covering itself with a layer of slime that protects them from sanitizers such as bromine and chlorine.
These bacteria can even be harmful. Some biofilms can contain:
- Pseudomonas Aeruginosas
- Mycobacterium Fortuitum
If you simply drain and fill the hot tub then you transfer almost all the old bacteria directly into the new water. This persistent biofilm can cause bacterial blooms that can leave you red and itchy.
This is why you want to clean your plumbing lines.
How to Drain Your Tub and Remove Biofilms
First, you want to add a line flush product to your hot tub water. Add this to the old water and circulate it for at least 20 minutes and up to four hours depending on the product direction.
NOTE: It’s not uncommon to develop a 4″ thick layer of brown/black foam covering the surface of the water as the long-established bacteria pulls away from the plumbing lines.
Next, you want to remove the filters and turn off the power to your hot tub.
Remove the filter(s) from the filter well and start cleaning the filters while the hot tub is draining.
Disconnect anything electrical running to your hot tub before you begin. You don’t want the hot tub turning on when there’s no water in it. Make sure the breaker is tripped and the power is disconnected.
NOTE: If you’re not comfortable with the electrical systems of your hot tub, or even a little unsure, please call a licensed electrician or Townley Pool and Spa to help.
Next, it’s time to start draining the hot tub.
Use a sump pump or the drain plug on your hot tub. Drain the hot tub leaving only the foot well full of water. A sump pump makes this process faster.
How to Clean Your Filters
Every hot tub has filters that ensure your water is clean and safe.
The filters remove any debris and other substances from your water. You replace your filters based on how often you use your hot tub and where it’s located.
If you have backup replacement filter cartridges, soak the filters for 24 hours using a diluted hot tub filter cleaner (according to the directions on the bottle). Make sure you use enough water to completely submerge one filter. If you have room, you can add more filters to the solution.
If you don’t have backup replacement filter cartridges, generously spray your hot tub filters with a hot tub filter cleaner and let them sit for about 15 minutes. Then, rinse them with clean water.
- Use spa filter cleaner from local hot tub store.
- Make sure you rinse your filters with water thoroughly after cleaning. Otherwise, it may cause foam in your hot tub.
How to Clean Your Drained Hot Tub
Once the water is removed from the hot tub you can wipe the interior surface with a hot tub surface cleaner.
Spray the inside of your hot tub and wipe it clean. Make sure not to leave any cleaner inside the tub. It could cause your water to foam.
Fill Your Hot Tub with Fresh Water
Once the old water is gone, your filters are replaced and your hot tub shell is clean, fill I with fresh water.
It’s a good idea to use a hose filter that fits on the end of your garden hose. This removes impurities such as copper, iron, and calcium that are present in your tap water. They can cause hard water and damage your hot tub.
Filling Your Hot Tub Using a Hose Filter
- Attach your hose filter to the end of your garden hose.
- Check all the drains on the hot tub to be sure they are closed.
- Double check that there is still no power to the hot tub.
- Turn on your hose and fill your hot tub to the optimal level as set by your hot tub manufacturer.
- Restore power to your hot tub and turn it on allowing the jets to run. If you need to prime your hot tub, do so now.
Start Your Hot Tub and Add Chemicals
- Test your water and adjust your pH levels to between 7.4 and 7.6, your Total Alkalinity (TA) levels to 80 ppm and your Calcium Hardness (CH) to 100 ppm.
- Shock your fresh hot tub water while the hot tub is running and allow it to continue to circulate.
- Adjust your temperature, if necessary, to between 100 degrees and 104 degrees Fahrenheit.
- Replace your cover and allow the spa to run for 24 hours to heat properly.
- After a day has passed, run the clean cycle on your hot tub and then check your pH levels, TA levels, and CH levels again.
If you perform this maintenance task on your hot tub right before the weather turns cold and again early in the spring then you minimize your workload while protecting your health at the same time.
Stop Biofilms from Returning
Maintaining high water quality is key to prevent biofilm. Enzyme-based products can help. Simply add the enzyme to your water weekly or monthly. This breaks down the oils and other contaminants that allow biofilms to grow.
Even with these treatments, you should use a line flush product at least once a year as part of your regular maintenance.
Additionally, soak your filters in a cleaning solution at least three times a year to prevent biofilms from coming back.
Look Out for Limescale
Limescale can coat your hot tub both on the shell and even the plumbing, giving biofilms yet another place to hide and even reducing the efficiency of your hot tub in the process. If you have limescale buildup, then you need to flush your system completely and change the water.
Once that is done, pay close attention to your pH levels and consider adding a limescale prevention chemical in the mix of your water.
Congratulations – you just drained and cleaned your hot tub.
Make sure to do this at least twice yearly for the best soaking.
If you would like some help taking care of your spa, contact our expert service team as we are happy to help!
Source: Swim University