Limescale and hard water: what plumbers can and cannot fix
Why taps, shower heads and water heaters fur up in Lisbon and the Algarve, what a plumber can do about it, and what to ask before buying a softener.
Hard water, briefly
Hard water carries dissolved calcium and magnesium, picked up as it passes through limestone. Heated or left to dry, it leaves limescale (calcário).
Much of the water in the Lisbon area and the Algarve is moderately hard to hard, and some private wells and boreholes are harder still. Hardness is usually given in mg/L of calcium carbonate (CaCO3); your water company publishes its water quality results, hardness included.
Is it a health problem?
No. Hard water is safe to drink; limescale is a nuisance and a cost, not a health risk. The reasons to deal with it are your appliances, your water heater's efficiency and the time you spend cleaning.
Where you will see it
- White crust on taps, shower heads and glass screens.
- Weaker flow from shower heads and tap aerators as they clog.
- Water heaters that heat more slowly, make noise or fail early, because scale coats the heat exchanger or the element.
- Toilet cisterns that stop sealing, and washing machines and kettles that scale up.
What a plumber can fix
- Descale or replace tap aerators, shower heads and cistern valves.
- Descale the heat exchanger of an esquentador or boiler during a service.
- On a termoacumulador, check and replace the anode and the element, and flush out the scale.
- Fit a scale-reducing filter on the cold supply to the water heater or boiler.
- Install a water softener, usually where the supply enters the home, with a bypass so you can keep unsoftened water for drinking if you prefer, or an under-sink filter for drinking water.
What a plumber cannot fix
Nobody can change the hardness of the mains water arriving at your meter. A softener treats the water after it, and needs salt and regular servicing to keep working. Devices sold as magnetic or electronic conditioners are not softeners; results reported for them vary, so ask for evidence and a trial period before you buy.
Before you buy a softener
- Test your water first: your supplier's published results, or a simple hardness test.
- Ask for the size that fits your household and the salt use per month.
- Ask about space, a drain connection and an electrical socket near the installation.
- Get two quotes that show the equipment, the installation and the yearly servicing separately.
Frequently asked questions
Can I just use vinegar?
For aerators, shower heads and taps, soaking in vinegar or a descaler works well as regular maintenance. Water heaters and boilers should be descaled by a professional during a service.
Will a softener save energy?
Less scale on the heating element or heat exchanger helps a water heater work as designed, and it can last longer. How much you save depends on your water and how you use hot water.