If you need to know how to empty a spa pool, the job is usually fairly straightforward. Most spa pools have a drain valve that allows the water to flow out, while inflatable models such as Lay-Z-Spa generally have a drain connection that can be used with a garden hose.
The important part is not just getting the water out. You also need to make sure you drain it somewhere appropriate, protect the spa and equipment while it’s empty, and take the opportunity to clean the shell and filters before refilling.
For most spa pools, I recommend draining and thoroughly cleaning the spa every few months, depending on how heavily it’s used and the manufacturer’s recommendations. Alpine Spas, for example, recommends a full drain and refill every 3 to 4 months.
What to know before emptying your spa pool
Before pulling the drain plug, there are a few things worth checking.
Turn the power off first
This is the most important step.
Turn the spa pool off at the isolation switch or mains supply before draining it. Don’t rely solely on the spa’s control panel.
The water level can drop below the pump, heater and filter intake as the spa drains. Running the equipment without sufficient water can damage components.
If your spa has a dedicated isolation switch, use it. If you’re unsure which switch supplies the spa, check the installation or owner’s manual.
Check where the water is going
Don’t simply open the drain and let several hundred litres of chemically treated spa water run towards the nearest stormwater drain.
Stormwater systems generally discharge to the environment without the same treatment as wastewater. Auckland Council information specifically identifies pool and spa pool water as something that should be kept out of stormwater drains.
New Zealand councils can have different requirements for disposing of pool and spa water, so check your local council if you’re unsure.
Where a suitable wastewater connection is available, this is often the appropriate option. Some councils also allow suitably treated water to be discharged onto your own property, provided it doesn’t run into waterways, stormwater drains or neighbouring properties.
Don’t drain during heavy rain
It’s sensible to avoid putting a large volume of water into the wastewater system during heavy rain. Some councils have specific restrictions around this because wastewater networks can become overloaded.
The exact rules vary by council, so check locally if you’re unsure.
Check your manufacturer’s instructions
Drain valves aren’t all designed the same way.
A hard-shell acrylic spa might have an external drain valve on the cabinet. An inflatable spa might have a drain connection on the base or side of the liner.
If you’re dealing with a particular model, the owner’s manual should take priority over generic instructions.
How to drain a spa pool
For a conventional hard-shell spa pool, the basic process is:
- Turn off the power at the isolation switch.
- Remove the spa cover.
- Locate the external drain valve.
- Connect a suitable garden hose if you need to direct the water somewhere specific.
- Open the drain valve according to the manufacturer’s instructions.
- Allow the spa to drain completely.
- Remove the remaining water from the footwell with a sponge, bucket or suitable wet vacuum.
- Clean the shell, jets and filters.
- Rinse away any cleaning residue.
- Refill the spa before restoring power.
Some spa pools, including Alpine models, have an external drain valve specifically designed for attaching a hose. Alpine’s instructions also recommend removing the remaining water from the bottom of the spa after draining.
How to empty a spa with a hose
Using a garden hose is one of the easiest ways to control where the water goes.
The basic idea is simple. Attach the hose to the spa’s drain outlet, place the other end where the water is permitted to discharge, and open the valve.
On some spas, the hose attaches directly to the drain valve. On others, you’ll need a hose adaptor supplied with the spa.
Using the spa’s built-in drain valve
If your spa has a threaded drain outlet:
- Turn the spa power off.
- Remove the drain cap.
- Attach the appropriate hose adaptor.
- Connect the garden hose.
- Position the other end of the hose at the approved discharge point.
- Open the drain valve slowly.
- Check that water is flowing where you expect it to.
- Leave the spa to drain.
For example, Alpine’s current spa instructions describe attaching a male-end hose fitting to the drain valve, connecting a hose and then opening the valve gradually.
The advantage of using a hose is that you can direct the water away from the spa rather than allowing it to flood the immediate area.
Just remember that a hose doesn’t make an otherwise unsuitable discharge location acceptable. The water still needs to be disposed of in accordance with the requirements that apply to your property.
How to drain a hot tub without a pump
You don’t necessarily need a separate drain pump to empty a spa.
There are three common options:
| Method | Advantages | Disadvantages | Best suited to |
|---|---|---|---|
| Built-in drain valve | Simple and designed for the spa | Can be relatively slow | Most hard-shell spas |
| Garden hose/siphon | Cheap and doesn’t require a pump | Can be slow and may not remove the last water | Portable spas and situations without a drain pump |
| Submersible drain pump | Very fast | Requires an additional pump and safe electrical setup | Large spas or awkward discharge locations |
If your spa has a built-in drain valve, that’s normally the first method I’d use.
Using a garden hose as a siphon
If you don’t have a usable drain connection or need to remove water from a low point, a garden hose can sometimes be used as a siphon.
The hose needs to be filled with water first. Once the hose is full, keep one end submerged in the spa and position the other end at a point lower than the spa water level. Starting the siphon allows gravity to pull the water through the hose.
This method works best when the discharge point is significantly lower than the spa.
However, don’t expect a simple garden-hose siphon to remove every last litre. Once the water level gets very low, you’ll usually need to remove the remaining water manually or use a suitable wet vacuum.
How to drain a Lay-Z-Spa
Lay-Z-Spa models are different from conventional acrylic spa pools, but they are designed to be drained using their drain connection.
Bestway’s instructions for Lay-Z-Spa-style products describe connecting a hose adaptor to the drain valve and directing the garden hose to the intended drainage area. Some models have a drain pipe on the bottom of the liner that can be connected directly to a garden hose.
The general process is:
- Turn off and disconnect the spa pump.
- Make sure the water isn’t hot enough to create a burn risk.
- Locate the drain valve or drain pipe.
- Connect the supplied or compatible hose adaptor.
- Run the garden hose to the approved discharge location.
- Open the drain valve.
- Allow the water to drain.
- Remove the remaining water from the liner.
- Clean and dry the spa before storing it if you’re packing it away.
The exact procedure varies between Lay-Z-Spa models, so check the manual for your particular model before disconnecting anything.
If you’re storing an inflatable spa, drying it thoroughly is particularly important. Bestway warns that storing the liner while it’s still damp can result in mould growth.
How to drain an Alpine Spa
Alpine Spas use an external drain valve on the spa cabinet.
The current Alpine procedure is:
- Turn the power off.
- Start with the drain valve in the locked position.
- Pull the drain valve out.
- Remove the drain cap.
- Attach the appropriate hose fitting.
- Connect your garden hose.
- Put the other end of the hose at the intended discharge location.
- Slowly push the drain valve towards the spa until water begins flowing.
- Adjust the valve if necessary to control the flow.
Alpine specifically warns that the power must be turned off before draining.
Once the main body of water has drained, there will normally still be some water sitting in the bottom of the spa and potentially in parts of the plumbing. For a normal drain and clean, removing the water from the shell is usually sufficient.
If you’re winterising or leaving the spa empty for an extended period, that’s a different job. Alpine’s long-term shutdown procedure involves additional steps to remove water from the plumbing, pumps and other components.
What to clean a hot tub with when empty
Draining the spa is an excellent opportunity to clean the shell properly.
You don’t need an aggressive chemical cleaner. In fact, using harsh products can create problems when you refill the spa, particularly if residue remains behind.
For routine cleaning, I recommend:
- A clean microfibre cloth
- Baking soda for stubborn marks
- A mild, low-strength all-purpose cleaner if appropriate for your spa’s surface
- Fresh water for rinsing
- A sponge or bucket for removing leftover water
Alpine’s cleaning guidance recommends baking soda or a low-strength all-purpose cleaner with a microfibre cloth for cleaning the acrylic shell. It also recommends thoroughly rinsing the shell afterwards so cleaning residue isn’t carried into the fresh water.
Pay particular attention to the waterline
The area around the normal water level can develop a scum line from body oils, cosmetics, sunscreen and other contaminants.
Wipe around the entire waterline rather than just cleaning the areas that look dirty.
Clean around the jets
The jet fittings and surrounding areas can collect grime and biofilm.
Wipe around the jets carefully. If your manufacturer’s instructions allow the jet fittings to be removed, you can clean behind them as well.
Don’t force a jet fitting that isn’t designed to be removed. Different spa manufacturers use different fittings.
Clean the filter
The filters deserve attention whenever you drain the spa.
Remove the cartridges and rinse them thoroughly. If they haven’t had a proper clean for some time, use a filter-cleaning product appropriate for your filter rather than relying solely on a garden hose.
A dirty filter can contribute to cloudy water and makes the filtration system work harder.
What to do after the spa has drained
Once the shell is clean, don’t rush straight into filling it without checking the equipment.
Have a quick look for:
- Cracked or damaged jet fittings
- Loose drain fittings
- Signs of leaks
- Damaged seals
- Dirty or damaged filter cartridges
- Debris around suction fittings
- Unusual staining or scale
- Damage to the cover
This is also a good time to clean the spa cover and inspect its underside.
If you notice a leak or damaged plumbing while the spa is empty, it’s much easier to deal with it now than after you’ve put several hundred litres of fresh water back in.
How to refill a spa after draining
Before refilling, make sure all drain valves are properly closed.
For many hard-shell spa pools, filling through the filter box is recommended because it helps reduce the chance of an airlock in the circulation system. Alpine, for example, recommends removing the filters and filling through the filter box before replacing the filters and restoring power.
Your manufacturer’s instructions should take priority because filling procedures differ between models.
Once the spa is full:
- Check that the water is at the manufacturer’s recommended level.
- Make sure the drain valve is closed.
- Check around the equipment area for leaks.
- Replace the filters.
- Restore power.
- Allow the spa to complete its startup or priming cycle.
- Test the water.
- Adjust the pH, alkalinity and sanitiser levels as required.
- Allow the water to circulate properly before using the spa.
Don’t turn the spa on while the water level is below the manufacturer’s required operating level.
How often should you empty a spa pool?
There isn’t one universal interval for every spa.
It depends on:
- How often the spa is used
- Number of bathers
- Whether people shower before using it
- How well the water is balanced
- How effectively the spa filters the water
- The manufacturer’s recommendations
Alpine Spas recommends draining and refilling every 3 to 4 months, while Consumer NZ notes that the appropriate interval depends on usage, showering habits and water maintenance.
If your water is continually difficult to balance, becomes cloudy or develops excessive scale despite proper maintenance, a drain and refill may be more appropriate than continually adding more chemicals.
Common mistakes when emptying a spa pool
Forgetting to turn off the power
This is the biggest mistake. Never allow pumps or heaters to operate without adequate water.
Draining into a stormwater drain
A stormwater drain isn’t simply a convenient hole in the ground. Pool and spa water can contain chlorine, salt and other contaminants that shouldn’t be discharged into waterways.
Using too much cleaner
You don’t need to soak the spa shell in household chemicals.
A small amount of suitable cleaner, followed by a thorough rinse, is generally preferable to leaving a heavy layer of cleaning product behind.
Leaving the spa empty in direct sunlight
An empty spa can be more vulnerable to heat and UV exposure than you might expect. Some manufacturers specifically warn against leaving an empty acrylic spa exposed to direct sunlight without its cover.
If you’re only draining the spa to clean it, get the job done and refill it rather than leaving it sitting empty for days.
Assuming every spa drains the same way
A portable inflatable spa, acrylic spa and wood-fired hot tub can have completely different drainage systems.
If you’re unsure, find the model number and consult the manufacturer’s instructions before removing valves or disconnecting plumbing.
When to call a professional
Draining and cleaning the shell is normally a straightforward DIY job.
Professional help becomes more appropriate if you need to:
- Disconnect or modify electrical equipment
- Repair pumps or heaters
- Access internal plumbing
- Repair a significant leak
- Disconnect hard-plumbed pipework
- Winterise complex equipment
- Diagnose an airlock or circulation problem that persists after refilling
- Make changes to the spa’s drainage or wastewater connection
Don’t disconnect electrical components simply because the spa is empty. If electrical work is required, use an appropriately qualified electrician.
If you’re planning to permanently change where the spa water drains, check with your local council or a qualified plumber rather than assuming an existing drain is suitable.
Frequently Asked Questions
Can I drain my spa pool onto the lawn?
It depends on your location, the condition of the water and local discharge requirements. Some councils allow spa or pool water to be discharged onto your own land provided it can soak into the ground without running into stormwater, waterways or neighbouring properties. Other areas have stricter requirements.
Check with your local council before doing this, particularly if the water contains significant chlorine, salt or other chemicals.
Can I drain a spa pool into a stormwater drain?
You generally shouldn’t assume that you can. Stormwater drains can discharge directly into streams, rivers or the sea, and chemically treated spa water can harm aquatic environments.
Auckland Council specifically advises keeping pool and spa pool water out of stormwater drains.
How do I drain a hot tub without a pump?
If the spa has a built-in drain valve, use that first. You can attach a garden hose to many drain valves and direct the water to an appropriate discharge point.
A garden hose can also be used as a siphon if the discharge point is lower than the spa water level, although this can be relatively slow.
How long does it take to empty a spa pool?
It depends on the spa’s water capacity, drain valve and hose diameter. A typical spa may contain several hundred litres or more, so draining through a small hose can take some time.
Don’t be tempted to increase the discharge rate beyond what your wastewater system or local council permits.
Should I clean my spa when I drain it?
Yes. A drain and refill is the ideal time to clean the shell, waterline, jets and filter. It also lets you inspect the spa for leaks, damaged fittings and other problems while the water is out.
How often should I drain my spa pool?
For many residential spas, a complete drain and refill every few months is reasonable, but the correct interval depends on usage and the manufacturer’s recommendations. Alpine Spas recommends every 3 to 4 months, while Consumer NZ notes that usage and water-care practices affect how often water needs changing.
Emptying your spa pool the right way
Learning how to empty a spa pool isn’t difficult, but there are a couple of things worth getting right.
Turn the power off before draining, use the spa’s proper drain valve or hose connection where possible, and make sure the water is discharged somewhere appropriate rather than into a stormwater drain. Once the spa is empty, clean the shell and jets, wash the filters and check the equipment before refilling.
If you’re using a Lay-Z-Spa, Alpine Spa or another specific model, follow its manufacturer’s drainage instructions because the valves and fittings can differ considerably.
Done properly, a drain and clean is more than simply getting rid of old water. It’s a useful part of regular spa maintenance and gives you a chance to start again with a clean shell, clean filters and properly balanced fresh water.
