To maximize the lifespan of a cartridge, always choose the clearest water. GeoPress® cartridges deliver ~350 cycles (250 liters / 65 gallons) while UltraPress® offer ~300 cycles (150 liters / 40 gallons). Water quality matters; avoid silt and sediment. Preemptively filter out silt and sediment with a handkerchief or t-shirt to extend the life of a cartridge.

The time it takes to press with your GeoPress® or UltraPress® will gradually increase over time. We recommend 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.

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.

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, etc. 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.

Grayl® cartridges contains non-woven ceramic fibers that have a high electropositive charge. These fibers 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 flavors, and odors.

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.

Proper maintenance for your GeoPress® or UltraPress® is crucial for optimal performance. After your adventures, ensure to follow these simple steps to keep your purifier in top shape. Start with a 'dry press' by pressing the wet purifier into the empty Outer Cup and disposing of excess water. Next, remove the cartridge and allow it to air-dry for 2-4 days. For the remaining parts, hand wash them with warm, soapy water and let them air-dry. To maximize the lifespan of the cartridge, store the unit assembled. With proper care, the cartridge can last up to three years.

Yes, 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).

Always add electrolytes into the clean drinking water side. Avoid adding flavoring 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 those situations, pour the clean drinking water into another water vessel and then add electrolytes or flavorings.

Size, capacity and weight! Both models offer the highest level of protection from waterborne pathogens (99.99% of virus, 99.9999% of bacteria, and 99.9% of protozoan cysts, including Rotavirus, Hepatitis A, Norovirus, Giardiasis, Cryptosporidium, E. Coli, Cholera, Salmonella, Dysentery). They also filter many heavy metals, chemicals, and microplastics.

GeoPress® filters and purifies 24 oz of water, ideal for individuals and groups looking for a high capacity. UltraPress® purifies 16.9 oz and is great for individuals with limited space or when traveling with small pack side pockets.

Grayl® filter and purifier bottles are made from: BPA-free polypropylene #5, food-grade silicone, TPE and ABS food-grade plastic. Our products are designed in Seattle, Washington, and manufactured by our partners in China with the exception of our cartridge media which is produced in the United States.