If you’re new to hot tubs, or just need a refresher, you might be relieved to know that cleaning your hot tub isn’t complicated or hard. But a thorough cleanse will take a little over 24 hours from start to finish. You won’t be working that whole time though; once it’s cleaned and refilled, you’ll run it for 24 hours to let the water chemistry stabilize.
Before we dig into how to deep clean your hot tub, it’s important to know that regular light cleaning is important to keep it clean. Weekly, you should clean the cover, wipe tub surfaces down like you would with your bathtub, and maintain the water chemistry. That means checking the pH, alkalinity, and sanitizer levels with a test kit and adjusting as needed. Your sanitizer will typically be chlorine or bromine, but the latter is gentler and more common. A deep, thorough clean like we lay out here should happen every 3-4 months.
Supplies You’ll Need
- Bleach and/or cleaning vinegar
- Hot tub cleaner that will also clean the plumbing
- Cover cleaner
- Filter cleaner
- Non-abrasive cleaning pads
- Nylon scrub brushes
- Submersible pump or pool cover pump
- Water test kit
How to Clean a Hot Tub
Step 1: Treat the Water
As long as there is no visible debris in your water, remove your filter cartridge. Add the hot tub cleaner to you water and circulate the water for 1 hour. Be sure the air jets are turned off—cleaners may cause water to foam—and that the water jets are open. If you haven’t thoroughly cleaned your hot tub in a while, you may want to run it for a couple of hours.
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While the cleaner is circulating is a good time to tackle the filter. Some filter cleaners require soaking whole thing in a bucket, but if you’ve been keeping your filter relatively clean, a fast-acting solution like Black Diamond Stoneworks Ultimate Spa Filter Cleaner will work great in 5 minutes. In either case, be sure to flush the filter with clean water after you’ve washed it.
Step 2: Drain the Water
Note: Before you drain your hot tub, check local rules and ordinances. Some areas may require you to send your treated hot tub water into the sanitary sewer system. This may mean routing it into a utility sink. If you’re allowed, you can recycle it to water your lawn—just be sure the pH is below about 7.5 so you don’t burn the grass, and move the hose around frequently to disperse the water.
The first thing to do is shut off the power to the hot tub at the main breaker. This is usually housed in a grey electrical box, located close to the hot tub.
Most hot tubs will have a drain with a hose connector—you can use this, but it will take hours to drain. The faster way is to use a submersible pump or a pool cover pump. Just connect a hose to the pump, drop it in the water, and plug it in. Stick around and make sure to turn it off when the tub is pumped out, as running the pump without water going through it can burn it out. There will be a little water that the pump won’t be able to suck out—you can open the drain for this.
Step 3: Clean the Tub
With the tub empty, you can clean the surfaces. Make a solution of 85 percent water and 15 percent bleach or cleaning vinegar, spray that on the tub surfaces, then scrub the tub down with non-abrasive cleaning pads (or nylon brushes for really tough grime or scum). Then wipe the hot tub clean with towels and flush it with fresh, clean water. You can leave the drain open to be sure you let all the cleaning solution and dirt wash out of the tub. Close the drain.
Step 4: Refill
Make sure the drain is closed, then install the cleaned filter, make sure the water jets are open, and start filling the hot tub with fresh, clean water using a hose.
While the tub is filling, clean the cover. Spray it down with a good cover cleaner, scrub it well, then wipe it dry. Make sure to use a cleaner with a UV protectant that will help prevent damage to the cover material due to the sun’s rays.
When the water level is correct, go to the main breaker and turn the power back on and start up the hot tub, making sure the air jets are off. Test the water and adjust the pH and alkalinity as needed to reach 7.2-7.6 for pH and 120-180 parts per million, then add your sanitizer at the proper amount for the volume of your hot tub. Circulate the water for about 30 minutes, retest, and adjust as needed.
Replace the cover and run the hot tub overnight between 80-90 degrees. Then retest the water, adjust as needed, and you’re ready to soak in it again.
Brad Ford has spent most of his life using tools to fix, build, or make things. Growing up he worked on a farm, where he learned to weld, repair, and paint equipment. From the farm he went to work at a classic car dealer, repairing and servicing Rolls Royces, Bentleys, and Jaguars. Today, when he's not testing tools or writing for Popular Mechanics, he's busy keeping up with the projects at his old farmhouse in eastern Pennsylvania.