People frequently confuse the different types of water recycling, often thinking that greywater is collected from washing machines, kitchen sinks and showers/baths, and is used for irrigation. Or, that rainwater harvested from the roof is potable, neither of which are true. At Aquaco, we specialise in both Grey water recycling and Rainwater Harvesting, the methods for which are explained below.

grey water system

Grey water is water that has been collected from bathroom sinks, baths and showers. It is generally high in surfactants and soaps among other things. Grey water recycling systems collect, treat and filter this water and use it to flush toilets. 

Rainwater is what it says on the tin. Rainwater is pure when falling from the sky, free from chemicals and contaminants. However, rainwater is harvested from the roof where it can be contaminated by pollution and various other things like leaves or even bird excrement.

By harvesting your own rainwater and recycling your grey water, you are drastically reducing the amount of potable/mains water that your household consumes. There are many other benefits to recycling your own water, the biggest one being a reduction in your water bill, particularly if you’re on a water meter. 

Using rainwater in your washing machine will also make it last longer, as rainwater is free from chemicals that make it ‘hard’, which causes a build up of limescale and reduces the lifespan of your appliances. The same goes for your garden. Plants are used to being watered by rain which doesn’t include the treatment chemicals that a mains water supply would. A rainwater harvesting system would allow you to water your garden for free, with better quality water – it’s a win-win. 

Grey water is collected from hand-wash sinks, showers and baths, but NOT kitchen sinks. This is because the use of a kitchen sink varies too much to treat it as minimally as our systems do. Think raw chicken, and you’ll understand why kitchen waste water is not included.

We also do not recommend Grey water for irrigation purposes, again, due to the nature of the water. If you do decide to use it for irrigation, there are some Dos and Don’ts (mostly don’ts) to adhere to:


Don’t use grey water on edible plants

Don’t use spray irrigation or pressurised attachments (even hose pipes can be risky). 

Do install a UV unit in the greywater tank to act as a biocide for any lingering bacteria. 

One of the biggest risks of using Grey water for anything except for toilet flushing is Legionnaires. The bacteria that cause diseases like legionnaires thrive in warm, wet environments, just like used bath water (see where I’m going with this?). Read our blog post which talks you through Legionella, Legionnaires disease and how to prevent it in water recycling. 

Being able to give water a second life is vital to helping conserve water. 70% of our planet is covered in water, but only 3% is usable to humans. Our population is growing exponentially so the demand for water is getting higher and higher every minute of every day. This together with a changing and therefore unpredictable climate, we all need to do our bit. If we do, then together we can save water, save money, and help to save the planet’s most valuable resource.