Pure water should be colorless, odorless and tasteless (although I think it tastes refreshing). You should be a little concerned if your water has started to taste like metal. There are several reasons why this happens, and while many are harmless, some of them need you to take immediate action.
Water can taste like metal if it’s contaminated with metals like iron, zinc, copper, manganese and arsenic. It can also taste metallic because of acidity or a heightened sensitivity to taste from certain conditions like pregnancy. If only the hot water is affected, then it is certain minerals (like sulphates) in the water or metal contamination within the hot water heater itself that is to blame.
In this article, I explain why your water tastes like metal. I’ve included how to know which problem is yours specifically, and where possible how to fix it.
Reasons Why Your Water Tastes Like Metal
The most likely reason your water tastes like metal, is because, well.. there’s metal in your water. But, that’s not the only reason. Here are all the reasons why your water tastes like metal and how to know which problem you have specifically. We’ve included the main metals at fault, as these are the most common reason for this horrible taste – but don’t worry, every possible reason is here, and of course how to fix it.
1. Individual Sensitivity
Smell and taste can be heightened in certain health conditions, like pregnancy. If you are suffering from pre-eclampsia, a zinc deficiency or undergoing chemotherapy water will often taste like metal. There is little you can do during these times, other than flavor your water, but thankfully most women report their water tasting normal almost immediately after these conditions have resolved.
People taking certain drugs (like the antibiotic metronidazole) can make water taste metallic. The effect usually goes away once you get off these medications.
Some people also have a naturally higher ability to detect certain smells and tastes. Even with safe levels of minerals in water, they may be able to detect their unique tastes – which is not usually something to be worried about.
2. Iron Contamination
Iron can very easily get into your water, either from old and rusty plumbing or natural sources (especially if your water comes from a well).
The following clues can help you decide if iron is giving your water its metallic taste:
- Rusty color
- Presence of brown residue at the bottom of your water container
- Confirmation through lab analysis or through at-home test kits
We have more information on how to know iron is in your water available here.
It’s not necessary to remove iron from water as it generally isn’t harmful, but if you want to get rid of the metallic taste, consider using a greensand filter, or installing a reverse osmosis system (read more about that here).
You may also need to consider changing the plumbing in your home if you think rusty pipes are leaching iron into your water. As this is a long-term issue that will only get worse.
3. Manganese
Manganese is another element that’s found in various minerals in the earth’s crust. It’s natural for groundwater (or even tap water in certain states) to have some level of manganese compounds, which can give water a metallic taste.
To identify whether manganese is present in your water, you can sometimes see a greyish or blackish tint to your water, as well as the metallic taste. However, this only happens at high concentrations, and in most cases, you’ll need to send your water to a nearby laboratory to have it tested to be certain.
Since manganese doesn’t pose significant health hazards, removing it from water is mostly a matter of preference. For this, consider using Reverse Osmosis systems or ion-exchange systems (these are common in under-sink filters and only a handful of water filter pitchers).
4. Arsenic
Unlike iron and manganese, Arsenic, when consumed with our water, can lead to toxic effects from skin problems to nerve damage, or even certain types of cancer.
An important point to note is that arsenic itself is virtually tasteless when dissolved in water. However, it is often found in environments that favors growth of certain types of microbes, which can give water a distinctive taste that some interpret as ‘metallic’.
If you are using groundwater (or are living in areas prone to arsenic contamination), it’s always a good idea to have your water sent to a lab for detection. Home-test kits are also available, but they tend to be less sensitive and specific than laboratory based tests.
Reverse osmosis systems, under-sink filters, and ultrafiltration are effective ways to reduce arsenic from your water – more on that here.
However, if you do detect arsenic in your water, we recommend collaborating with your local authorities to decide the best way forward, considering how toxic arsenic is.
For more information on the different contaminants that can be in your water, EPA has a great PDF available here.
5. Copper contamination
Like iron, copper is a common mineral, but it can also be found in copper wiring, certain plumbing, and in copper vessels.
Copper has a distinctive metallic taste, and some people even report a faint odor with copper-containing water.
It can make your water look bluish in color (especially when present as sulphates), which can be a reason to suspect copper contamination in your water.
Thankfully, removing copper from water is not too difficult. Simple ion-exchange filters or reverse osmosis systems can usually remove sufficient copper to make the water free of metallic taste.
6. Zinc contamination
Many steel pipes are galvanized with a zinc coating, so it’s quite possible for there to be too much zinc in your water.
Zinc does not give water a distinct color, so often, the only way we suspect zinc contamination is if you to have zinc-galvanized plumbing in your home or in your water supply system, and have metal-tasting water.
Normally, zinc doesn’t pose a direct risk of health. If you simply want to remove zinc to get rid of the taste, try reverse osmosis or ion exchange filters, which are effective at removing up to 99% zinc from your water.
You can also consider having your plumbing inspected and changed if necessary.
7. Acidity (Low pH) of water
The ideal pH for drinking water is around the neutral mark, i.e. 6.5 to 8.5. If you weren’t sure, pH is just how we measure how acidic something is!
At lower pH (i.e. high acidity), water can start to slowly corrode the metals it comes in contact with, which could be zinc, copper or iron. This will naturally lead to a metallic taste.
The easiest way to detect low pH is to use simple available test-kits, which show different colors based on the pH level that your water has.
Treating this condition involves buying and adding commercial products called ‘acid neutralisers’ (like soda ash) to your water.
However, it’s often important to detect how the water became acidic in the first place, as you may want to consider contacting the local authorities.
Warm Metallic Tasting Water
Many people report that water tastes more metallic when it is warmer – and with good reason.
One possible explanation for warm water tasting more ‘metallic’ is that minerals tend to be more soluble as the temperature of water increases. Our tongue can taste these minerals better when they are dissolved better, which can lead to a more metallic taste in hot water:
- Aluminium sulphate.
- Calcium hydroxide.
- Fluorosilicic acid.
- Sodium silicofluoride.
But another reason is that there is metal contamination in your hot water heater. These metals would not be contaminating the cold water line, so you will only experience the metal taste with hot water.
To check for this, you will need a plumber, and unfortunately you might need a new system. In the meantime, make sure to always use the cold water tap to fill your drip machine, pots and kettles.
