What Happens When a Water Filter Expires?

Don't stress over expired filters.

By: Alyssa Scavetta

When is the last time you changed your water filter? 6 days, 6 months, 6 years? They say nothing lasts forever (well, almost nothing), and for good reason. For those that have done their research, invested time, energy and money into purchasing a water filter to protect their home — you likely know that water filters have an expiry date. The more you procrastinate replacing your water filter past its expiration date, the more you expose your home to all sorts of unwanted contaminants.

While choosing the right filter can be hard, getting clean water doesn’t have to be.

No matter when you purchased your filter, eventually it will expire and need to be replaced. Depending on what type of filtration system you’ve purchased, it could be a significant cost.

So what if you could just skip it, and leave it in? It probably still gets the job done, right? Well, that’s where you’re wrong. Let’s take a look at how long water filters last and what happens when they expire.

Do unused water filters expire?

We get this question a lot, as people often purchase replacement filters in bulk and wonder if it’s ok for them to sit on a shelf until they’re needed.

In short, no, unused water filters do not expire. There is no set shelf life for water filters, as long as they’re not exposed to any moisture. That’s the key — moisture is what makes water filters work, and without that, they’re sitting pretty and ready for use at any time. However, if you use a filter once and then don’t use it again for a long period of time such as with a vacation home — its brief exposure to moisture means you’ll still have to replace it at some point.

What happens when a used water filter expires?

In short, when a water filter has trapped, targeted, or sifted all bacteria and contaminants from entering your water supply, that filter, in turn, takes the fall. Depending on your filter type, after 2 months, 6 months or 6 years, your filter could be covered in bacteria, rendering it unable to perform up to optimal spec, and turning it into a petri dish for all other contaminants to thrive, and those very contaminants that you tried to prevent from entering your house will be released into the water supply.

According to Healthline, a German study of expired water filters revealed that their “filter had a biofilm growing on it, and in some cases the bacteria colony counts in the filtered water was up to 10,000 times those in the tap water.”

According to Healthline, a recent German study of expired water filters revealed that their “filter had a biofilm growing on it, and in some cases the bacteria colony counts in the filtered water was up to 10,000 times those in the tap water.”

This means that bacteria like E. coli and Legionella, as well as giardia and cryptosporidium could be waiting in the wings ready to make its way into your morning cup of water.

Additionally, your home water pressure can be affected, as your filter is working overtime to try and reduce the sediment and contaminants from entering your water. This means you can go from a water pressure of 8 GPM+ to much, much lower. Imagine showering and trying to wash the soap out of your hair with a slow trickle of water? That’s what you’ll experience if you avoid replacing your water filters beyond their lifespan.

Understand which water filter you have

Stocking up on fresh filters means that you get continued enjoyment of clean, healthy water around your whole house. But how do you know which filter to purchase? Let’s take a quick look at the differences between each filter type:

  • Activated Carbon: Acts like a magnet, pulling contaminants closer to them and away from the water supply. This helps to reduce pharmaceuticals, herbicides, pesticides, and VOCs.
  • Catalytic Carbon: Targets chlorine and chloramines.
  • Ion-Exchange or Reverse Osmosis: Acts as a screening mechanism to trap and prevent bacteria smaller than 0.01 microns from entering the water supply. This helps to eliminate heavy metals like lead and mercury and remove fluoride.
  • Absolute Sub-Micron Mechanical Filtration: Captures asbestos and chlorine resistant cysts like cryptosporidium and giardia.

The type of filter you have may affect how long it lasts, so consider this when purchasing a new water filtration system or subsequent replacements.

The benefits of replacing your water filtersfilterexpire_blog_body

Because there are so many different filter types, there are many benefits to gain from installing fresh filters.

  1. Optimal reduction of contaminants, bacteria, and sediment: The newer the filter is, the more it will perform to testing standards. For reverse osmosis, for example, that means you can continue to enjoy a 95% reduction in fluoride and mercury, a 97% reduction in chlorine and arsenic, as well as a 99% reduction in lead and asbestos. No harm, no foul water.
  2. Increased water pressure and flow rate: The average household flow rate is 2-3 gallons-per-minute (GPM) for kitchens, 1.5-3 GPM for the shower, 2-4 GPM for the dishwasher, and 3-5 GPM for the washing machine. A new water filter will ensure that your pressure keeps up to snuff. For example, if your home is less than 3500 sq. ft. and you have 3.5 bathrooms or fewer, you should not experience any noticeable drops in water pressure. If you have a larger home, we offer our 1,000,000 Gallon Rhino Whole House Filter System to ensure your home doesn’t experience any pressure drop.
  3. Better taste and smell: When you replace your filter you get back clean, great-tasting water by removing 97% of chlorine in regular tap water, as well as other contaminants. When it comes to your drinking water, no taste and odor is great taste and odor. It’s better water for a better you.

How Water for Life can help

Need fresh filters but don’t want to deal with another errand to run?

Aquasana’s Water For Life program makes it easy to swap filters on time as they need to be replaced. Whether you’re already an Aquasana customer or buying your first water filter — Water For Life ensures you’ll never have to worry about keeping up with filter lifespans or expiration dates.

Get filters auto-delivered when they need to be replaced — plus receive 15% off the price of replacement filters and an extended warranty on your filtration system. Our no-contract Water For Life program makes filter replacements simple and cost-effective! Never worry about dealing with expired water filters again.