Eric Roy, Ph.D. | Hydroviv's Scientific Founder   

Much like changing a car’s oil is necessary for a car to operate, replacing the cartridge in your Hydroviv water filter is necessary to ensure that your filter is producing safe drinking water for you and your family. This article discusses the most frequently asked questions that we get about cartridge replacement.

Why Do I Have To Change My Water Filter Cartridge?

The performance of a water filter cartridge against dissolved and particulate contaminants is dictated by two main factors: #1. pore structure and #2. active media blend. A water filter must be changed regularly because as water flows through the filter over time, the pore structure can become clogged with particulate matter and active media becomes saturated with chemicals. When the capacity of either is exceeded, the filter no longer performs as designed.

How Do I Know When It’s Time To Change My Water Filter Cartridge?

While it’s easy to tell if particulate matter has filled up the filter’s pores (flow rate slows down), it’s not as straightforward to tell if a filter has been saturated by dissolved chemicals without laboratory testing. This is where 3rd party testing & certifications come in. For example, as part of Hydroviv’s NSF Certification Program, our drinking water cartridges were shown to filter chemicals like PFAS, lead, and VOCs for over 720 gallons before performance tapered, which translates to a 6 month replacement interval for over 95% of Hydroviv customers.

What Happens When You Don’t Change Your Filters’ Cartridge? 

When a filter is used beyond the capacity, filtration performance drops and can reach a point where the filter can release contaminants into the water, a process known as “avalanching.” This is why we tell people that if they decide not to replace the cartridge, they are better off disconnecting their filtration system.

Are There Other Factors That Create Exceptions to The 6 Month Rule?

While over 95% of Hydroviv users are best served by a 6 month replacement interval, we do have users that use a longer or shorter changeout interval. For example, a filter used by a large family that drinks a lot of water or has a high amount of particulate matter could require more frequent cartridge replacements. Conversely, an occasionally-used filter can probably be changed out less frequently, though we don’t ever recommend letting any filter be used for over 9 months for hygiene reasons. 

This video shows how easy it is to replace the cartridge in your Hydroviv filter. 

Other Articles We Think You Might Enjoy:
Here's why you shouldn't drink or cook with water from the hot side of your faucet:
Stop using TDS/ppm meters to test the quality of your water
Why home water filters are better for the environment:

Analies Dyjak, M.A. & Christina Liu, B.S. | Science Team   

Whenever we pour something down the drain or flush the toilet, it’s easy to think “out of sight out of mind.” However, the things we put down the drain can impact water quality in a big way. This article highlights exactly what not to pour or flush down the drain.

Where Does The “Stuff” That Goes Down The Drain Go?

All of the water flushed or washed down the drain goes through your city’s sewer system and into the wastewater treatment facility. The water that’s used to flush your toilet, take a shower, or wash your dishes all end up in the exact same spot. The wastewater treatment facility will treat the used water for a variety of pollutants. Once the water goes through the various processes, it’s released into local waterways to be recycled for a number of different purposes (including drinking water!).

Do Wastewater Treatment Plants Remove “Everything”?

It’s easy to assume that a wastewater treatment plant might remove absolutely everything from incoming wastewater. That isn’t entirely the case. Wastewater treatment plants do a really good job at removing larger solids, biological/bacterial contaminants, and sediment. They do not remove many chemicals, pharmaceuticals, hazardous materials, industrial waste, or pesticides. This puts a lot of pressure on drinking water treatment plants to carry a majority of the tap water purification. Some wastewater treatment plants are outdated and aren’t able to remove these types of pollutants, while others are not even required to do so. Click here for an in-depth video on how wastewater treatment plants actually work.

To help ease the burden on wastewater and drinking water treatment plants, here’s a list of things you should never pour or flush down the drain:

Pharmaceuticals: Old or unwanted prescription/over-the-counter medications should never be flushed down the toilet or sink. Water treatment plants are unable to remove most pharmaceuticals, which means that trace amounts end up in our tap water. Small amounts or levels below therapeutic doses are currently not a cause for concern but if people continue to dispose of medications down the drain, these levels of pharmaceuticals may accumulate. For guidance on how to properly dispose of pharmaceuticals, check out the FDA’s best practices for disposal of unused medicines.

Grease: Aside from the obvious reasons why you should never pour grease, oils, or fats down the drain, doing so can actually cause issues at a much larger scale. Whatever grease you pour down the drain congeals with everyone else's, and can form a mass in the sewer system. The mass can block other wastes from passing through, creating a major sewage blockage (like we saw in Detroit, MI). Check your city’s municipal utility company to see if they have a cooking oil collection program. If not, the best recommendation is to collect the used oil in a leakproof jar, seal it up, and throw it away in the trash.

Motor Oil: Never pour used motor oil or other automotive fluids (including antifreeze, solvents and gasoline) down a drain in your house or garage, into a storm drain, onto the soil, into a waterway, or in a manhole on a sidewalk. Used motor oil can contain toxic heavy metals such as zinc, lead, and cadmium that can contaminate drinking water. In fact, one quart of oil poured down a storm drain can contaminate one million gallons of water. One pint of oil can produce a slick of approximately one acre of water. When oil enters a body of water, a film develops on the surface that blocks out sunlight that plants and other organisms need to live. Please note that unlike cooking oil, you also cannot dispose of motor oil in the trash, and many cities will issue stiff fines for dumping toxic waste into landfills. Always bring used motor oil to local used oil collection centers. 

Paint: Whether it’s latex, acrylic, or oil, paints can clog your pipes and potentially leach toxic compounds into the water. If you can, first try to see if the leftover paint can be reused. School drama clubs or community theaters will often be happy to take unused paint! If the paint can’t be reused and must be disposed of, avoid throwing it away. Bring paint to local household hazardous waste collection locations/events. Don’t clean brushes in the sink, but use rinse buckets, and let the paint residue settle overnight from the old rinse water before pouring the water down the sink, leaving the congealed and dried paint at the bottom of the bucket, where it can be peeled or scraped off and thrown away.

Important Takeaways:

Wastewater treatment plants are primarily designed to treat the biological materials in the water, but are NOT equipped to treat the water for chemicals such as pharmaceuticals, cooking oil, household grease, motor oil and other automotive fluids, paint, photographic chemicals and others. A good rule of thumb is, when in doubt, don’t pour it down the sink or into sewer or storm drains. Check with your local authorities for toxic waste disposal locations.

Other Articles We Think You Might Enjoy:
Don't Drink or Cook With Water From The Hot Side of Your Faucet
6 Myths About Drinking Water
Why Home Water Filters Are Better For The Environment:

Using a reusable water bottle and filling it up with filtered tap water can reduce your carbon footprint and save you money.

There are many misconceptions and myths about drinking water, some of which can be potentially harmful or can result in negative health effects. Our Water Nerds unpack some of the most well-known drinking water myths in this article.

Updated 4/13/22

Since this article was first written, we've continued getting inquiries about endocrine disruptors and methylated mercury, and more recently, lead and PFAS contamination, and how people become exposed to these chemicals. Different routes of contamination include not only drinking water, but also through food, so we wanted to spend some time explaining how this happens.  

What is Bioaccumulation?

Bioaccumulation refers to the process of toxic chemicals building up inside of an organism’s body. This happens when a chemical is consumed or absorbed, and the body cannot catabolize or excrete it quickly enough. A contaminant will bioaccumulate inside the body if the rate of intake of the contaminant exceeds the rate it is excreted. Mercury is a well-known chemical that can bioaccumulate in humans. We commonly hear about mercury exposure resulting from eating fish such as tuna (or other large predatory fish). However, mercury as well as many other harmful chemicals can also be found in drinking water supplies across the United States.
Chemicals that tend to bioaccumulate are stored in cells and not exposed to direct physical or biochemical degradation. These chemicals can collect and hide-out, particularly within adipose tissue (fat cells). Fatty mammary tissue often contains the highest concentrations of toxic chemicals. These chemicals in our mammary tissue are then passed along to infants when nursing. 

What is Biomagnification?

Biomagnification refers to the process of toxic chemicals increasing in concentration as they move throughout a food chain. Bioaccumulation and biomagnification often work hand-in-hand; one animal accumulates chemicals in the body (bioaccumulation) and then a larger predator consumes that smaller animal such that the chemical is passed along to the predator. The chemical “magnifies” as the resulting concentrations increase in the predator because it likely consumes large quantities of that particular prey throughout its lifetime (biomagnification). As top-level predators in our own food chain, humans tend to collect high concentrations of toxic chemicals in our bodies.

Does Lead Bioaccumulate?

Lead is a particularly toxic contaminant because it is able to persist and bioaccumulate in the body. In humans, the principal organs affected are the central and peripheral nervous system and the cardiovascular (brain and nerves), gastrointestinal (GI tract), renal (kidneys), endocrine (hormone secretion), immune, and hematological (blood) systems. The American Academy of Pediatrics and other health organizations have determined that there is no safe level of human lead exposure, and children are especially vulnerable to exposure to and bioaccumulation of lead.

Bioaccumulation and PFAS

Poly- and perfluoroalkyl substances (PFAS) are a class of chemicals widely used in a variety of applications, including firefighting foam, nonstick coatings, stain-resistant fabrics, and even food packaging and cosmetics. While different forms of PFAS have been in use since the 1950s, relevant studies of its effects on humans did not occur until decades later. In 2013, scientists in Spain published the first paper analyzing the accumulation of different PFASs in samples of various human tissues. They discovered that PFHxA accumulated in highest concentrations in brain and liver, while PFBA levels were highest in kidney and lung, and PFOA was the predominant compound in bone, and finally PFOS accumulated primarily in lung, liver and kidney. The CDC has reported that PFAS has been found in the blood of 97% of Americans.

What are Persistent Bioaccumulative Toxics (PBTs)?

PBTs are a particular group of chemicals that threaten the health of humans and the environment. Examples include methylmercury, polychlorinated biphenyls (PCBs), dichloro-diphenyl-trichloroethane (DDT), and dioxins. PBTs are considered extremely dangerous to both humans and wildlife because they remain in the environment for a very long time without breaking down, then bioaccumulate and biomagnify in ecosystems (including ours).

PBTs can also travel long distances and move between air, water, and land. DDT, a notorious environmental pollutant, was developed as a synthetic insecticide in the 1940s. Sprayed over crops, DDT would then wash into water supplies and contaminate lakes, ponds, streams, rivers, and oceans. Small organisms such as plankton and algae absorb DDT through the water. Smaller fish then consume the contaminated algae and plankton. Larger predatory fish then consume the smaller fish. Eventually, large predatory birds or humans eat the contaminated fish.

Despite being banned in the United States over 40 years ago, DDT is still found in soil and water supplies today. In addition, humans contain the highest concentrations of DDT when compared to other organisms.
Exposure to PBTs has been linked to a wide range of toxic effects in humans and wildlife. Some of those adverse effects include but are not limited to disruption of the nervous and endocrine systems, reproductive and developmental problems, immune system suppression, and cancer.

How Can I Minimize My Contaminant Exposure?

1. Avoid eating species of fish that are long-lived and high on the food chain such as tuna, marlin, shark, swordfish, king mackerel, and tilefish.
2. Use a high quality water filter that removes PFAS, Lead, and PBTs (e.g. DDT, Dioxins, BPA, Phthalates) from contaminated drinking water before the chemicals get a chance to accumulate in you.

More Articles We Think You'll Love:
Heavy Metal Toxicity: What You Need to Know
PFAS is Being Detected Everywhere
Is PFAS Exposure Toxic to the Immune System?