Is it Safe to Drink Water from an Old or Expired Filter?

Drinking filtered water is a sure sign of enjoying safe water that tastes great. Whenever you purchase a water filter, the manufacturer will advise you to replace it in 2-3 months. Is this really necessary, or can you continue using your old filter?

Filtered water is only safe to drink if the filter is in proper working condition. If you use an old filter, you risk drinking contaminated water. Studies have shown that old filters provide a conducive environment for biofilm growth, which means the water will most likely be contaminated with bacteria. Change water filters every 3-6 months even if they aren’t used frequently.

Read on to learn more about what happens when you don’t change your water filter, how long filters last, and some best practices around replacing your water filters, in general.

What happens if you don’t change your water filter?

Additionally, water filters work by trapping the contaminants in your water. Over time, these contaminants get too many in the filter and if you continue using it beyond the recommended period, there is a good chance they will start leaking into the water. So, the next time you see your refrigerator light warning you to change your filter, you had better do it.

Changing your water filter every 2-3 months might sound excessive and unnecessary. But if you consider the consequences of using an old water filter, you will be happy to replace yours on time.

Here are some of the other problems of not changing your filter in good time:

  • Bacterial contamination
  • Buildup of minerals
  • Buildup of contaminants
  • Breakdown of filter media
  • Reduced water pressure

Bacterial contamination

Unfortunately, there might be dangerous bacteria growing in an old water filter because of stagnation and a lack of activity inside the filter. Some studies show that this bacteria could be seriously concerning.

In the study that was carried out in Germany, colony counts of bacteria found in old filters were almost 10,000 times that found in tap water. This means that if you do not change your water filter as recommended by the manufacturer, you are better of just drinking tap water.

The buildup of minerals

Minerals are essential and necessary for proper growth and development. However, when consumed excessively, the minerals can cause all manner of health complications. For instance, the mineral buildup could result in kidney stones which will greatly reduce the quality of your life.

Water filters usually trap these minerals; if you don’t replace them on time, the excessive amounts of minerals in the filter could permeate into your drinking water.

The buildup of contaminants

It’s not just the minerals that build up in the water filter – the filter will also have a contaminant buildup. This could be anything from pathogens to suspended solids in the water. As these contaminants build up, they could get into the water, which will defeat the purpose of installing a water filter in the first place.

Faulty filters

Every manufactured thing has a shelf life, and water filters are no exception. Old filters will no longer work as they are supposed to. A faulty filter will not do a good job of filtering out the contaminants from water. You might even notice a change in the taste/color of the water.

Reduced water pressure

The older your water filter is, the more susceptible it is to clogging. This is mostly due to contaminant buildup, which is a serious threat to water quality. A clogged filter will affect the flow rate of water, and you will have to deal with the reduced water pressure, which can be really annoying.

Can a bad water filter make you sick?

An old water filter can be a biofilm hotspot.

In addition to bacteria, the filter will also have an accumulation of all the contaminants that are filtered from the water. This exposes you to a horde of waterborne diseases including but not limited to Cyclosporiasis, Cryptosporidiosis, Giardiasis, Escherichia coli Infection, Hemolytic Uremic Syndrome (HUS), Harmful Algal Blooms (HABs), Hot Tub Rash, Legionellosis, Norovirus Infection, Shigellosis, Swimmer’s Ear, and Swimmer’s Itch.

How long do water filters really last?

Water filters last anything from 2-6 months, depending on the brand and type of filter.

Generally speaking, filters used in commercial settings last longer, while those used in residential settings have a shorter shelf life. That said, there are some exceptions so you may want to check the manufacturer instructions on your specific brand to know the exact shelf life.

Also, how long the water filter lasts will depend on how much water is filtered. On average, domestic water filters will need replacing after filtering around 40-100 gallons of water. That means larger households might need to replace their filters sooner than smaller ones.

How do I know when my water filter needs replacing?

Always stick to the timelines suggested by the manufacturer.

However, there are times when you might need to replace your filter sooner than the manufacturer recommends. For instance, if you start detecting an odor in your water, it could indicate a failed or old filter that needs replacement.

Another sign of an old or failing filter is a decrease in water pressure.  You could also check the visual indicator on your water filter (typically on filters that have clear containers) and you will know if the filter has gotten dirty.

Are water filters expensive?

Contrary to common belief, water filters are not expensive. It is actually cheaper to install a water filter than to keep buying bottled water. The amount you spend on your water filter depends on the type and brand.

For instance, if you want a pitcher water filter, you can get one for under $30, but if you want a whole house water filter, you can get one for under $500. Suffice it to say, there is a good water filter for almost any budget. Follow this link to see our top recommended water filters at different price points.

Final thoughts

As we have seen, using an old filter is a health hazard. Always check the manufacturer user instructions before installing the water filter to know how long you should use it before replacing it. Also, if you notice the water quality deteriorating, replace your water filter ASAP.

The last thing you want is to deal with a nasty waterborne disease that was 100% preventable.