8 Eco-Friendly Ways to Dispose of Old Hot Tub Water

Jennifer Rhodes

By Jennifer Rhodes · Updated

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When it's time to drain and refill your spa, you've got several hundred gallons of water to get rid of.

Seems a little wasteful to just put it down the drain, right?

You'll be pleased to learn that there are actually plenty of handy (not to mention eco-friendly) ways to give old hot tub water a second lease of life—for all sorts of common tasks around your home.

Here are eight different ways to recycle your spa water, by putting it to good use.

1. Water the plants

Plants being watered

If you have a hot tub, your home likely has some landscaping around it. You may have a garden, trees, shrubs, or plants in flower pots. And just like humans, plants need water to drink.

Did you know that you can use your old hot tub water to water the plants?

There's a catch to watering your plants with recycled spa water though: the sanitizing chemicals in the water need to fall to less than 1 ppm (high levels of chlorine or bromine could kill your plants). The pH should also be between 7.0 and 7.2.

To achieve this, you will need to leave the hot tub uncovered and let the water sit for three to four days before using it on your yard.

Never use old spa water on your vegetable garden or other plants that you plan to eat—it's not going to be safe to consume.

Be aware that if you have a saltwater spa, you should also not use the water from it on plants, as most won't tolerate the salty water.

2. Wash the car

Washing a car

One of my favorite ways to reuse old hot tub water also gets me a sparkling clean car. It's perfect for that initial rinse of all the dirt that builds up on the sides of vehicles.

You will need a long hose (long enough to get from the spa to where your car is parked). Simply attach the hose to your spa's drainage outlet on one end, position the other end near your car, and start washing.

Keep in mind you might not be able use a nozzle as the pressure won't be as high as it would be from the regular water supply.

One thing to watch out for is if your neighborhood has a community water watch patrol or hose pipe ban in place, as they could question you about the constant flow of running water. You may need to explain that it is coming from the spa and not the municipal water.

Another word of warning: if the hot tub is saltwater, it's best not to use it on your car as it can damage the paint job over time.

3. Clean outdoor areas

House with clean driveway

If you have outdoor areas you need to keep clean, like decks or patios, the water out of your hot tub is excellent for this.

Driveways in particular get a lot of dirt caked in over time, which turns grey pavement to black in some spots. By using your regular outdoor cleaner along with spa water to wash down outdoor areas, nothing goes to waste.

Some other things you can clean are porches, fences, carports, and gazebos or pavilions. Once again, you will need to have a long enough hose to get the water from point A to point B.

There may be other items like tools, benches, or other equipment you may want to be cleaned at the same time, and you can do that too. Just be careful to avoid any food preparation surfaces like outdoor kitchens though—used spa water is considered grey water and is not food-safe.

4. Clean the trash cans

Trash can

Trash cans harbor bacteria that can cause odor if left unchecked. Nobody likes that kind of odor near their home, but rinsing them out regularly will help you avoid this problem.

Lucky for you, you have a whole hot tub of water to recycle. Starting with the garbage is the perfect way to put old spa water to work.

And the best part? You don't even need to let the chemical levels drop before using spa water to clean the trash cans—they're not picky.

Trash cans also bring about unwanted critters like raccoons, stray cats, or other animals that can cause damage or make a mess. They don't mean to; they're just after snacks of course. But by using your spa water to rinse out the trash cans, it will help block the smell and keep pests at bay.

5. Store water for emergencies


Natural disasters can happen at any time, and having some spa water on hand can come in handy in the event of emergencies like power outages.

Those with water pumps will have no water if the power goes out, plus it's always possible that there could be a problem with the municipal water supply (a concern where I live in California due to earthquake risk).

The water you're recycling is considered grey water, so it has limited uses, and you'll obviously need a separate supply of emergency drinking water.

But water stored from your hot tub can be used to flush toilets, for example. Just make sure to pour the water into the bowl and not the tank.

6. Water the lawn

Beautiful house with a large green lawn

Everyone loves a beautiful green lawn, so you'll be pleased to learn you can use hot tub water to water the grass. It's another great way to recycle old spa water—and conserve municipal water in the process.

Like the first suggestion on this list, it's really important to get the spa water down to the right chemical levels (1 ppm sanitizer and pH of 7.0-7.2) first so you don't damage the grass. The same rules apply to your lawn as any other plants.

Make sure to distribute the water evenly over the lawn's surface. You don't want to create pools or floods in any particular areas.

And again, if it's salt water, you won't be able to use this tip or you risk killing the grass.

7. Keep your home foundation from cracking

Dry, cracked ground

If you live in a dry area, you may not see rain for weeks. Many places like this have a severe problem with cracking ground around homes, which can even shift the foundation in extreme cases.

By recycling the water from your hot tub, you can help avoid this problem. When draining your spa, walk around your property with the hose, wetting the ground around your home to keep it from cracking.

Be sure to check with city officials if this is allowed in your area. The last thing you want is a citation while trying to save your property.

8. Fill up a pet pool

Ducks in a kiddie pool

Pets love to have fun and keep cool on those hot summer days. They're no different than us in that they love to splash around in water (well, maybe not cats, but dogs sure do).

Why not fill up a plastic kiddie pool with your old spa water and let your fur babies cool off?

These pools don't cost much, and the water is already paid for from the first time you used it in the hot tub.

Just be sure to dry them before they go back in the house, or you'll end up with spa water inside where you definitely don't want it!

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