- The Filta-Max system has been specifically designed to optimize both the capture and recovery of Cryptosporidium and Giardia.
- The filter is made of open-cell foam discs that have been compressed to give a nominal porosity for the capture of Cryptosporidium and Giardia.
- After sampling, the foam is decompressed, enabling the captured organisms to be recovered by a simple washing and concentration procedure.
- U.S. EPA Method 1623 and UK DWI-approved.
- More Cryptosporidium and Giardia tests are done worldwide using the Filta-Max system than all other filtration technologies combined.
- Consistently recovers high numbers of target organisms.
- High volumes of both finished water (up to and above 1000 liters) and raw water (up to 50 liters) can be filtered to provide greater sensitivity.
- Samples can be concentrated to 25 mL without centrifugation.
- The filter operates at sampling flow rates of up to 4 liters per minute.
Is Filta-Max approved by the U.S. EPA?
Yes. In April 2000, the U.S. Environmental Protection Agency (EPA) approved the Filta-Max system for use in Method 1623.
How the Filta-Max system works
The Filta-Max module comprises multiple layers of open-cell foam discs that are compressed to create a filter with a nominal pore size to effectively trap Cryptosporidium and Giardia. After sampling, the filter is processed by releasing the compression of the foam discs and washing, enabling all captured material to be recovered. It is a simple yet extremely efficient system.
To sample, the filter module is placed in a reusable housing, which is attached to the required sampling source. A head pressure of 0.5 Bar (7.5 psi) is required to create a flow, and the recommended operating pressure is 5 Bar (75 psi). This pressure will create a flow rate of 4 liters per minute, which is particularly beneficial when sampling large volumes of water.
After filtration, the module is removed from the housing and placed in the wash station. IDEXX provides both an automatic wash station and a manual version. The foam discs are decompressed by removing a bolt in the module and then washed with an elution buffer using expansion/compression cycles.
The volume of buffer is then reduced to between 25 and 50 mL by concentrating through a membrane, negating the need for high-volume centrifugation.
How to use
Connect the housing to the required water source for sampling
Remove the filter module from the housing.
Place the module in a wash station and wash with elution buffer.
Concentrate the wash buffer using a 3-µm membrane.
Repeat steps 3 and 4 to give a final volume of 25 mL.
Frequently asked questions
Does the Filta-Max system have any other approvals?
Yes, the Filta-Max system is also approved by the UK government for the regulatory sampling of 1,000 liters of drinking water.
What volumes of water can be filtered using the Filta-Max system?
The system is efficient for both raw and finished water. The filter has been approved for sampling 50 liters of raw water in Method 1623 by the US EPA. Other U.S. EPA-approved filters are limited to sampling 10 liters of raw water. The Filta-Max system is approved in the UK for sampling 1,000 liters of finished water.
What flow rates can be achieved with the Filta-Max system?
The Filta-Max system can operate at a flow rate of up to 4 liters per minute.
What are the recommended pressures for sampling?
A minimum pressure of 7.5 psi is required. 50 psi–75 psi is the recommended sampling pressure.
What are the shelf life and storage conditions for the Filta-Max filter module?
The shelf life is 18 months from the date of manufacture. Store module in a dry place (16°C–24°C), away from direct sunlight. Do not freeze. Do not refrigerate prior to use.
What recoveries can be achieved with the Filta-Max system?
Recoveries are consistently in excess of the minimum required by the regulations.
How does the cost of the Filta-Max system compare with other filters on the market?
The Filta-Max system is approximately half the cost of other U.S. EPA-approved filters.
What is the variability of the method?
Variability is low. Relative standard deviations are up to 50% lower than other U.S. EPA-approved filters.