How Reverse Osmosis Works

Osmosis is a process that begins with two bodies of water that each have a different concentration of solute, low and high. The two bodies of water are separated by a semi-penetrable membrane which allows the lower concentrate solution to pass into the higher concentrated side, and in doing so the concentration of solvents is equalized between the two sides. Take freshwater and salt water for example – the fresh water contains no solvent (salt), where the salt water contains… lots. Through osmosis, the solvent would become equally distributed between the two until they share the same concentration of solvent – they are now both equally salty.

So Reverse Osmosis, or RO for short, is the opposite process. When pressure is applied to, let’s say your drinking water supply, the water now passes back through the membrane the other way, and away from salts, minerals, and contaminants. Now you’re left with a cleaner, safer, and more delicious end product.
It’s pretty common knowledge that our tap water contains chlorine – if you’ve ever caught a funky or chemical sort of smell from your taps, that’s likely the culprit – but there are also plenty of other salts and minerals that can be present if the water isn’t given the right treatment at the tap.

Now whilst these minerals aren’t dangerous to your health, they will stop you from getting the most out of your humble tap water. Take a delicious, freshly brewed coffee for example. The minerals found in tap water can have adverse effects on the way the flavour compounds are extracted from the bean, leading to a sour, bitter, or just bland cup of coffee – not a great way to start your day!

Alongside the problems of funky smells and bad beans, untreated water can lead to your household

appliances degrading more quickly thanks to scale build up. Scaling occurs in appliances that are constantly being fed hard water, where the calcium and magnesium present in the water will lead to limescale build up and the inevitable demise of your poor kitchen kettle. Even if the limescale is treated with a descaling solution, these concoctions are comprised of harsh, acidic chemicals that can be tricky to handle responsibly. The reverse osmosis process is able to deal with these pesky contaminants and minerals before they ever get a chance to wreak havoc on your appliances, leaving you with a better brew and a happier, longer-lasting kettle.

Whether a reverse osmosis system will benefit your day to day water experience or solve any hard scale issues depends on the hardness of your water. You might feel like you have a handle on how hard your water is, but it is recommended that you get a clear measurement of the total dissolved solids (TDS) in your water supply using a proper TDS meter. This metric is measured in parts per million (ppm), with an acceptable feed for optimal drinking water sitting at around 150ppm.

As well as the regional water type, other factors such as flow rate and total water volume should be considered when specifying any water treatment solution, and RO systems are no different. We always recommend not only testing your water yourself, but speaking to an expert who can help you understand what system best suits your needs.