What Can I Do with the Grey Water from My Hot Tub?

Every few months you should be draining and refilling your hot tub. Whilst it may seem like a tedious task it will help increase the life span of your hot tub and ensure the water is safe to use. Failure to change your hot tub water regularly means the water can harbour nasty bacteria and harmful chemicals.

As hot tub users we know the different cocktail of chemicals we use to keep the water clean. Whilst these chemicals are safe for us in the short-term, this does not mean they’re always safe if the water is reused for other purposes or left for longer than four months. Old water from your hot tub is called grey waste, the same as what is stored in a caravan or motorhome and disposed of at special locations.

So, where should I drain my hot tub water and how do I go about it?

How to Drain Your Hot Tub

There are two common ways to drain your hot tub using the hot tub drain valve or submersible pump.

Hot Tub Drain Valve Method

You will notice that your hot tub has drain valves built in, making your life a little easier. Using the drain valve takes a longer than emptying with a submersible pump.

After following the pipe flush process for your hot tub (see the manual), you will need to:

  1. Turn the hot tub off and unplug
  2. Find your drain valve, your hot tub may have two, a primary and an auxiliary
  3. Use the primary to drain out most of the water
  4. Open the secondary drain to clear out the internal bleed lines
  5. Clean and carry out hot tub maintenance as needed

Submersible Pump Drain Method

Submersible pumps are a fantastic way to drain your hot tub quickly. Typically, the process takes around 10 minutes depending on the size of your hot tub.

After following the pipe flush process for your hot tub (see the manual), you will need to:

  1. Ensure no power is running to your hot tub
  2. Place the submersible pump in the deepest area of the hot tub
  3. Run the hose to your drain (or wherever you are getting rid of your water)
  4. Turn the pump on until the hot tub is empty
  5. Remove the submersible spa and carry out any other hot tub maintenance as needed

Commonly people siphon their hot tub water straight into a drain. Once completed, they use a wet and dry vacuum to suck away any residue and dry the jets.

However, if you would prefer to put your water to good use then some people use it for watering their garden or grass. Ahead of time, and if the hot tub is not in use, reduce the chlorine in the water. If you monitor the PH level of your hot tub it is unlikely that the grey water will contain anything harmful to plants, grass, or wildlife – particularly when reducing the chlorine content. Therefore, you can safely use it to hydrate your garden. Some people also use their grey waste to wash cars, bikes, and other outside equipment.

If draining directly into your garden be aware of any foundations or structures that could be disturbed. With the average four-person hot tub holding 719 litres of water it is all too easy to saturate the ground and cause problems. It is best to drain water as far away from any structures, such as a hot tub base or your home, when possible.

If you have any questions or would like more information about spa maintenance, please get in touch.

Back to blog