
Grayl Water Filter FAQs
General
1. What is the difference between the UltraPress® and the GeoPress®?
Size, capacity and weight! Both variants ensure top-tier defence against waterborne pathogens, boasting efficacy rates of 99.99% for viruses, 99.9999% for bacteria, and 99.9% for protozoan cysts, encompassing threats such as Rotavirus, Hepatitis A, Norovirus, Giardiasis, Cryptosporidium, E. Coli, Cholera, Salmonella, and Dysentery. Additionally, they effectively filter numerous heavy metals, chemicals, and microplastics.
The GeoPress® model purifies and filters 24 oz of water, catering to individuals and groups seeking ample capacity. Meanwhile, the UltraPress® variant purifies 16.9 oz, making it an excellent choice for individuals with space constraints or for those traveling with compact packs featuring small side pockets.
2. What is the difference between the Covert and Nature collections?
The Covert and Nature collections differ only in colour. Both collections offer the same level of protection. Covert features low visibility and Nature features high visibility.
3. Can I add electrolytes or other flavouring into a Grayl® after filtering and purifying?
Yes you can. Experience the hydration benefits of electrolyte-infused water in a UltraPress® or GeoPress® when equipped with a One-Way Electrolyte & Drink-Mix Valve (available since April 2023). Remember to incorporate electrolytes into the clean drinking water side.
Avoid adding flavouring or electrolytes directly into a cartridge not equipped with a One-Way Drink Mix Valve, as it can diminish the cartridge's lifespan and efficacy. In such cases, transfer the purified water to another container before adding electrolytes or flavourings.
4. What materials are Grayl® filter & purifier bottles made from? And where are the products made?
Grayl® filter and purifier bottles are made from: BPA-free polypropylene #5, food-grade silicone, TPE and ABS food-grade plastic. Grayl’s products are designed in Seattle, Washington, and manufactured by their partners in China with the exception of their cartridge media which is produced in the United States.
Filtering and Precautions
5. What type of water does Grayl® filter and purify?
GeoPress® and UltraPress® cartridges filter and purify most freshwater sources. Avoid using them with salty or brackish water. When treating freshwater, start with the cleanest water available, such as streams and rivers.
Grayl's activated carbon effectively adsorbs many chemicals, pesticides, herbicides, heavy metals, and more. However, it is not designed for industrial disasters, coal ash spills, high lead levels, mercury, nuclear disasters, high tannin concentrations, or water with toxic blue-green algae (e.g. cyanobacteria). Find another water source in those situations.
6. How does Grayl® filter and purify?
Grayl® cartridges contains non-woven ceramic fibres that have a high electropositive charge. These fibres effectively block and trap microorganisms and particulates, ensuring that submicron contaminants are removed through electroadsorption. Additionally, the cartridge is equipped with ultra-powdered activated carbon, which efficiently adsorbs chemicals, heavy metals, bad flavours, and odours.
7. Can a Gray® be used in freezing temperatures?
Yes but avoid using cartridges after 3 or more freeze/thaw cycles. Ensure the protection of your UltraPress® and GeoPress® in freezing temperatures by keeping it filled with water and insulated in a jacket or sleeping bag.
8. Can a Grayl® be used with hot or boiling water?
No. And avoid temperatures above 50°C (120°F) to prevent damage to the purifier media. Never use the Grayl® in the microwave.
9. How do I avoid cross-contamination?
To avoid contamination, use the Spout Cap. If dirty water comes in contact with the Inner Press, wash the Grayl (NOT the cartridge) with soapy water and rinse thoroughly. Alternatively, dilute contaminants by pressing and agitating water through a GeoPress® or UltraPress® purifier bottle 5-7 times.
10. What is the best way to fly with your Grayl®?
When an aeroplane ascends to its cruising altitude, the cabin pressure decreases, causing the air inside the Grayl® to expand. To prevent any leakage, it is recommended to use a One-Way Silicone Valve. This valve will reduce the likelihood of leaks from occurring. Alternatively, you can fly with your bottle either completely empty (without any water to leak) or completely full (without any air to expand). Once you have reached the cruising altitude, you can proceed to use the Grayl normally.
Lifespan
11. How long does a Grayl® filter and purifier last?
To maximise the lifespan of a cartridge, always choose the clearest water. GeoPress® cartridges deliver ~350 cycles (250 litres / 65 gallons) while UltraPress® offer ~300 cycles (150 litres / 40 gallons). Water quality matters; avoid silt and sediment. Filter out silt and sediment with a handkerchief or t-shirt to extend the life of a cartridge.
12. How do I know when it’s time for a new cartridge?
The time it takes to press with your GeoPress® or UltraPress® will gradually increase over time. Grayl recommends replacing the cartridge once the 'press time' reaches approximately 25 seconds (or three years have passed since the first use). Please note that colder water may require longer pressing time and does not necessarily mean the cartridge needs to be replaced.
13. Is it ok to filter water with high tannin concentrations?
Tannins, which are organic compounds naturally released from decomposing vegetation and trees, have the potential to cause any filter to clog prematurely. Tannins have the ability to turn water tea-coloured and form blackwater rivers when present in high concentrations, it is advisable to seek an alternative freshwater source when using your Grayl® UltraPress or GeoPress.
14. What is the shelf life of a cartridge?
An unused and airtight cartridge can be stored for up to 10 years. Once opened, use it for 3 years or until press time is ~25 seconds.
15. How do I clean and store my Grayl®?
Proper maintenance is essential to ensure optimal performance of your GeoPress® or UltraPress®. After your adventures, it's important to follow these straightforward steps to maintain your purifier in peak condition. Begin with a 'dry press' by pressing the wet purifier into the empty Outer Cup and disposing of any excess water. Then, remove the cartridge and allow it to air-dry for 2-4 days. Hand wash the rest of the components (NOT the cartridge) with warm, soapy water and let them air-dry. To prolong the cartridge's lifespan, store the unit fully assembled. With diligent care, the cartridge can remain effective for up to three years.
Information cited from Grayl 2024, correct as at 25.3.2024 and may be subject to change without further notice.