Water hardness
Increased levels of calcium and magnesium in the water within our area makes our water moderately hard to very hard.
Your Water
Water hardness across the UK varies depending on the local geology. Minerals can dissolve into the water as it passes over and through the ground. The amount of minerals that dissolve into the water is dependent on the type of rock.
In some areas, such as Devon, Cornwall and Wales the rocks are hard meaning very few minerals dissolve and this is why the water in these areas is soft. In the Bristol Water area, the rocks are predominantly limestone, a sedimentary rock containing lots of calcium and magnesium.
Being a soft rock, limestone easily dissolves, increasing the levels of calcium and magnesium in the water and making the water hard. Although there can be some seasonal variation, all the water in the Bristol Water area is classed as moderately hard to very hard.
What is hard water?
According to the World Health Organisation (WHO) guidelines, water is considered ‘hard’ and will produce limescale where the level of calcium carbonate is above 200 milligrams per litre (mg/l or parts per million). The table below shows how hard water is classified:
| Level of calcium carbonate (mg/l) | Classification |
| 0-50 | Soft |
| 51-100 | Moderately soft |
| 101-150 | Slightly hard |
| 151-200 | Moderately hard |
| 201-300 | Hard |
| Above 300 | Very hard |
The map below shows typical Bristol water hardness. More detailed information specific to your area can be found using the water quality postcode checker.
Is hard water bad for you?
No, hard water is not harmful to health. There is some evidence of a relationship between water hardness and cardiovascular health, possibly related to the beneficial properties of magnesium and calcium in the diet.
Can hard water be problematic?
Some people find that it can have a drying effect on the skin, which may exacerbate existing skin conditions.
Although hard water is completely harmless, it can cause problems within the home, such as:
- Scaling of hot water systems, washing machines, dishwashers, kettles and irons.
- Limescale and ‘tide marks’ in and around sinks, taps, baths, showerheads and toilets.
- Scum on hot drinks, especially tea, after reacting with oils and tannins in the tea leaves.
- Poor lather from soaps and detergents.
Answers to your questions about water hardness
What you can do
- Descale your appliances regularly to help maintain efficiency. With kettles, rinse out the particles regularly or use a limescale remover product. Be careful to follow instructions, and ensure the product is taken out, and the kettle rinsed before using it.
- Keep the temperature of your hot water below 60°C to minimise limescale formation.
- Use a jug filter that contains ion exchange resin beads to reduce kettle limescale and scum on cups of tea.
- Add Dead Sea Salts to bath water to soften it. This can help reduce skin irritation.
- Consider installing a domestic treatment device, like a water softener, water conditioner or scale inhibitor.
Why we don't soften the water supply
There’s no water quality standard that requires us to soften water. Additionally:
- Not all our customers want their water supply softened, so customers can make their own choice as to whether to install a domestic treatment.
- Soft water is more corrosive to metal pipework, which could lead to water quality issues, such as discoloured water associated with iron pipework, and could increase the risk of lead dissolving into the water from old lead pipes.
Water conditioners and softeners
Water conditioners
Water conditioners do not soften the water and are used to protect hot water systems and household appliances.
The most common types are electric and magnetic water conditioners. These devices prevent limescale build-up. This effect is thought to be temporary, so for best results, the device should be fitted as close as possible to the unit heating the water. As they do not soften the water you will not notice any change to the amount of soap or detergent used, or a reduction in the amount of limescale forming in your kettle.
The other type of is a chemical conditioner which adds a small amount of polyphosphate to the water. This combines with the calcium and magnesium to stop limescale forming when the water is heated. These units should always be installed by a qualified person to ensure they do not affect the quality of your drinking water.
Water softeners:
Water softeners are used to remove the calcium and magnesium minerals from the water, therefore limescale is not produced when the water is heated. Unlike physical water conditioners, the effect is permanent. It also means you will use less detergent and soap.
The two most common types of devices fitted in domestic properties are ion exchange salt softeners and reverse osmosis systems.
- Ion exchange salt softeners replace the calcium and magnesium minerals with sodium. The water passes over resin beads contained within the unit. The sodium ions on the resin are swapped with the calcium and magnesium ions in the water. Eventually there are not enough sodium ions left. More sodium ions are added to the resin by flushing the resin with a salt solution. This process is known as regeneration.
This type of softener is relatively cheap to buy and operate, and easy to install. However, because they increase the level of sodium in the water, it is recommended that at least one tap in the property is supplied by un-softened water for drinking and cooking purposes. - Reverse osmosis systems not only remove calcium and magnesium from the water, they also remove other minerals and metals that may be present in the water. They work by forcing the water through a semi-permeable membrane. The membrane has lots of microscopic holes big enough to let water molecules through whilst excluding larger molecules. This type of device is normally more expensive than ion exchange softeners and requires more power to operate.
With both types of softeners, it’s important to ensure they are installed by a qualified person in accordance with the Water Supply (Water Fittings) Regulations 1999.
Home treatment units should always be operated and maintained in accordance with the manufacturer’s instructions. It is also recommended that a bypass is installed to provide you with a water supply should the unit fail or malfunction.
What you can do
- Descale your appliances regularly to help maintain efficiency. With kettles, rinse out the particles regularly or use a limescale remover product. Be careful to follow instructions, and ensure the product is taken out, and the kettle rinsed before using it.
- Keep the temperature of your hot water below 60°C to minimise limescale formation.
- Use a jug filter that contains ion exchange resin beads to reduce kettle limescale and scum on cups of tea.
- Add Dead Sea Salts to bath water to soften it. This can help reduce skin irritation.
- Consider installing a domestic treatment device, like a water softener, water conditioner or scale inhibitor.
Why we don't soften the water supply
There’s no water quality standard that requires us to soften water. Additionally:
- Not all our customers want their water supply softened, so customers can make their own choice as to whether to install a domestic treatment.
- Soft water is more corrosive to metal pipework, which could lead to water quality issues, such as discoloured water associated with iron pipework, and could increase the risk of lead dissolving into the water from old lead pipes.
Water conditioners and softeners
Water conditioners
Water conditioners do not soften the water and are used to protect hot water systems and household appliances.
The most common types are electric and magnetic water conditioners. These devices prevent limescale build-up. This effect is thought to be temporary, so for best results, the device should be fitted as close as possible to the unit heating the water. As they do not soften the water you will not notice any change to the amount of soap or detergent used, or a reduction in the amount of limescale forming in your kettle.
The other type of is a chemical conditioner which adds a small amount of polyphosphate to the water. This combines with the calcium and magnesium to stop limescale forming when the water is heated. These units should always be installed by a qualified person to ensure they do not affect the quality of your drinking water.
Water softeners:
Water softeners are used to remove the calcium and magnesium minerals from the water, therefore limescale is not produced when the water is heated. Unlike physical water conditioners, the effect is permanent. It also means you will use less detergent and soap.
The two most common types of devices fitted in domestic properties are ion exchange salt softeners and reverse osmosis systems.
- Ion exchange salt softeners replace the calcium and magnesium minerals with sodium. The water passes over resin beads contained within the unit. The sodium ions on the resin are swapped with the calcium and magnesium ions in the water. Eventually there are not enough sodium ions left. More sodium ions are added to the resin by flushing the resin with a salt solution. This process is known as regeneration.
This type of softener is relatively cheap to buy and operate, and easy to install. However, because they increase the level of sodium in the water, it is recommended that at least one tap in the property is supplied by un-softened water for drinking and cooking purposes. - Reverse osmosis systems not only remove calcium and magnesium from the water, they also remove other minerals and metals that may be present in the water. They work by forcing the water through a semi-permeable membrane. The membrane has lots of microscopic holes big enough to let water molecules through whilst excluding larger molecules. This type of device is normally more expensive than ion exchange softeners and requires more power to operate.
With both types of softeners, it’s important to ensure they are installed by a qualified person in accordance with the Water Supply (Water Fittings) Regulations 1999.
Home treatment units should always be operated and maintained in accordance with the manufacturer’s instructions. It is also recommended that a bypass is installed to provide you with a water supply should the unit fail or malfunction.
What you can do
- Descale your appliances regularly to help maintain efficiency. With kettles, rinse out the particles regularly or use a limescale remover product. Be careful to follow instructions, and ensure the product is taken out, and the kettle rinsed before using it.
- Keep the temperature of your hot water below 60°C to minimise limescale formation.
- Use a jug filter that contains ion exchange resin beads to reduce kettle limescale and scum on cups of tea.
- Add Dead Sea Salts to bath water to soften it. This can help reduce skin irritation.
- Consider installing a domestic treatment device, like a water softener, water conditioner or scale inhibitor.
Why we don't soften the water supply
There’s no water quality standard that requires us to soften water. Additionally:
- Not all our customers want their water supply softened, so customers can make their own choice as to whether to install a domestic treatment.
- Soft water is more corrosive to metal pipework, which could lead to water quality issues, such as discoloured water associated with iron pipework, and could increase the risk of lead dissolving into the water from old lead pipes.
Water conditioners and softeners
Water conditioners
Water conditioners do not soften the water and are used to protect hot water systems and household appliances.
The most common types are electric and magnetic water conditioners. These devices prevent limescale build-up. This effect is thought to be temporary, so for best results, the device should be fitted as close as possible to the unit heating the water. As they do not soften the water you will not notice any change to the amount of soap or detergent used, or a reduction in the amount of limescale forming in your kettle.
The other type of is a chemical conditioner which adds a small amount of polyphosphate to the water. This combines with the calcium and magnesium to stop limescale forming when the water is heated. These units should always be installed by a qualified person to ensure they do not affect the quality of your drinking water.
Water softeners:
Water softeners are used to remove the calcium and magnesium minerals from the water, therefore limescale is not produced when the water is heated. Unlike physical water conditioners, the effect is permanent. It also means you will use less detergent and soap.
The two most common types of devices fitted in domestic properties are ion exchange salt softeners and reverse osmosis systems.
- Ion exchange salt softeners replace the calcium and magnesium minerals with sodium. The water passes over resin beads contained within the unit. The sodium ions on the resin are swapped with the calcium and magnesium ions in the water. Eventually there are not enough sodium ions left. More sodium ions are added to the resin by flushing the resin with a salt solution. This process is known as regeneration.
This type of softener is relatively cheap to buy and operate, and easy to install. However, because they increase the level of sodium in the water, it is recommended that at least one tap in the property is supplied by un-softened water for drinking and cooking purposes. - Reverse osmosis systems not only remove calcium and magnesium from the water, they also remove other minerals and metals that may be present in the water. They work by forcing the water through a semi-permeable membrane. The membrane has lots of microscopic holes big enough to let water molecules through whilst excluding larger molecules. This type of device is normally more expensive than ion exchange softeners and requires more power to operate.
With both types of softeners, it’s important to ensure they are installed by a qualified person in accordance with the Water Supply (Water Fittings) Regulations 1999.
Home treatment units should always be operated and maintained in accordance with the manufacturer’s instructions. It is also recommended that a bypass is installed to provide you with a water supply should the unit fail or malfunction.