How to Clean a Water Filter: Step-by-Step

Every type of water filter needs occasional cleaning to maintain a steady flow rate. With every use, it traps the sediment and debris it removes from your water. As this buildup grows, water flows more slowly until a quick refill becomes minutes of squeezing and pressing. 

If you're halfway through a long, exhausting hike, that's the last thing you need. So, how do you clean a water filter? 

How to Clean a Hollow Fibre Water Filter

A hollow fibre filter is refreshingly low-maintenance. All it needs is clean water, and a quick rinse after each trip keeps the flow fast and the element fresh for next time. 

1. Take It Apart

Pull off the bottle, lid and any cap so you can reach the filter element. The element does all the hard work, so it is the part that needs the most attention.

2. Rinse the Filter Element

Run clean water over the underside of the element to carry off the dirt and sediment collected during the day. A gentle shake or tap helps shift anything stubborn. Keep going until the water runs clear and the normal flow rate returns.

3. Wash the Other Parts

The bottle, lid and mouthpiece can go straight in the dishwasher. The filter element cannot, so set it aside and rinse it by hand. Leave everything to drain and dry fully before packing it away. 

4. Dry It, Then Store It

Let the filter element dry fully before storing it, since a filter packed away damp will breed mould and off-tastes. Once dry, keep it somewhere cool, dark and dry, ready for your next adventure. 

What Happens If You Don't Clean It?

If you don't clean your water filter, you probably won't notice anything wrong at first. The water still flows, and the filter still does its job, so it's easy to set it aside and forget about it. But all the dirt, sediment and bacteria the membrane has strained out is still trapped inside, with nowhere to go until you rinse it through. 

Leave it that way for a few trips and the effects start to show: 

• The flow slows down: Sediment, bacteria and protozoa build up against the membrane, and it takes much longer to fill your bottle. 

• The slowdown becomes permanent: Left long enough, the clogging sets in, and even a thorough rinse will not fully restore the flow.

• Hygiene suffers: Stored damp or dirty, the filter gives mould, mildew and biofilm a place to grow, which leaves the water tasting stale and musty.

• The filter wears out early: One that is never maintained clogs for good well before the end of its rated life, which means a replacement sooner than necessary.

Whether it is a filter for hiking or for emergency preparedness, a few minutes of care keeps it fast, clean and ready for the moment you need it.

How Often Should You Clean a Water Filter?

You should rinse your water filter whenever the flow starts to slow, and give it a proper clean after every trip. During long or continuous use, a quick rinse every few days keeps it moving.

Additionally, some water sources clog filters much faster than others. The dirtier the source, the faster the filter clogs, so a muddy river, a silty lake, or a stagnant pond will reduce the flow much sooner than a clear mountain stream. 

You might need to rinse the filter several times a day in muddy conditions, while a thorough rinse at the end of the trip is usually enough after filtering clean mountain water.

How Do You Sanitise a Water Filter?

While rinsing clears out the dirt in your water filter, it does not kill microorganisms that can grow inside the filter, which is where sanitising comes in. That's why it's a good idea to sanitise it before storing it for several weeks or longer.

To sanitise, use a disinfectant suited to water filters, such as a chlorine or chlorine dioxide solution, and dilute it exactly as the label says. Draw or run it through the filter, then leave it to work for the contact time the product specifies.

Once the time is up, flush several rounds of clean water through until no trace of the sanitiser is left. Do this before you pack the filter away, and you have done the single best thing to keep mould at bay.

How Do You Dry and Store a Water Filter?

Dry the filter completely before storing it in a cool, dry, well-ventilated place. Storing it while damp can lead to mould growth and permanent damage.

Start by draining out as much water as you can, then leave the filter to air-dry somewhere with a bit of airflow and out of direct sun. Make sure to give it ample time to dry, since the fibres hold water you cannot see.

Once the filter is dry, temperature is the next thing to consider. If temperatures are expected to drop below freezing, never let a used filter freeze. Water trapped inside the hollow fibres can expand as it freezes, causing tiny cracks that permanently damage the filter. Keep it somewhere warm overnight, such as inside your sleeping bag.

Get Ready for the Next Adventure 

A well-maintained water filter does not take much work. Rinse it after each trip, sanitise it before long-term storage, and replace the filter element when it reaches the end of its life. Take care of it, and it will provide clean, reliable water for years to come.

Good maintenance keeps a filter performing well, but choosing the right filter matters just as much. With Bachgold® filters, you can treat water from natural sources with confidence during your outdoor adventures 

All our products are able to remove bacteria and protozoa in the water. If you’re looking for added defence, the Squeeze and Straw are also highly effective against viruses. They require no chemicals or batteries, making them a practical choice for hiking, camping and emergency preparedness.

For every purchase, a portion of our revenue goes into the Viva con Agua Nepal drinking-water project, helping communities gain more reliable access to safe drinking water. 

Shop the Bachgold® filter today!