Coldstream FTO+ filter: operation, use and limits
The Coldstream FTO+ is a filter element intended in particular for certain gravity filtration systems. It combines a porous ceramic outer shell with internal filter media, including activated carbon.
Its effectiveness should not be presented in a general or absolute manner. Performance must be examined contaminant by contaminant, based on test reports corresponding exactly to the FTO+ model and the conditions under which the measurements were carried out.
1. Filtration combining ceramic and activated carbon
The ceramic exterior part constitutes a first physical barrier against certain particles present in the water. The activated carbon placed inside the filter acts by adsorption on certain compounds, in particular those which can influence the taste or odor of the water.
However, the actual reduction of a contaminant depends on several parameters:
- its nature and concentration in water;
- the volume of water already filtered;
- the filtration rate;
- the quality of the water used;
- the condition and maintenance of the filter;
- the precise conditions adopted during the laboratory tests.
2. Performance to be verified contaminant by contaminant
It is not accurate to state that a filter generally eliminates microplastics, heavy metals, pesticides, medications, bacteria and viruses without specifying the results obtained for each substance or microorganism.
A test report should normally indicate:
- the contaminant sought;
- its concentration before filtration;
- its concentration after filtration;
- the percentage reduction measured;
- the volume of water filtered at the time of measurement;
- the testing protocol or standard used;
- the exact reference of the filter tested.
The results obtained in the laboratory should not be automatically extended to all contaminants in the same category or to all conditions of use.
3. Taste, odor and chlorine
Activated carbon can help reduce certain tastes and odors present in water, especially when they are related to chlorine. The importance of this improvement nevertheless depends on the composition of the water, the flow rate and the condition of the filter media.
The filter does not necessarily remove all dissolved minerals. However, the maintenance of minerals should not be presented as a particular health benefit without precise analysis of the water and without suitable proof.
4. Compatibility with gravity fountains
The Coldstream FTO+ filter can be installed on certain gravity systems when the filter dimensions, threaded rod diameter, seals and available tank space are compatible.
Compatibility should be checked for each fountain model. It does not mean that the filter is manufactured, approved or certified by the other brands of gravity systems cited.
5. Capacity and duration of use
The capacity of a filter must be indicated in accordance with the technical documentation corresponding to the reference sold. It does not constitute a guarantee of identical duration for all users.
Replacement may need to occur sooner when:
- the flow rate decreases significantly despite proper cleaning;
- the taste or smell of the water changes;
- the original water contains a lot of sediment;
- the ceramic is cracked or damaged;
- the ceramic becomes detached from its base;
- the time or volume limit indicated by the manufacturer has been reached.
Several different capacities should not be announced simultaneously, for example 1,500 liters and 3,000 liters, without specifying whether these values correspond to a filter, a pair of filters, a system equipped with several filters or different test conditions.
6. Ceramic maintenance
The exterior surface of the ceramic can gradually become loaded with particles. Cleaning must be carried out in accordance with the manufacturer's instructions, using clean water and suitable equipment.
Too aggressive cleaning can wear out the surface, weaken the ceramic or reduce its thickness. The filter must be replaced if it has a crack, breakage or separation at the base.
7. Limitations of use
A gravity filter should not be presented as a universal guarantee of drinking water. For water from wells, boreholes, rivers or from a source whose quality is not controlled, a prior analysis is necessary.
This analysis makes it possible in particular to identify microbiological, chemical and mineral risks. The treatment system must then be chosen based on the contaminants actually detected.
If in doubt about the microbiological safety of water, it is necessary to follow the recommendations of the competent health authorities. Filtration does not automatically replace disinfection when it is necessary.
8. Manufacturing and control of the porous structure
Filter ceramic is a porous material whose pores are not all exactly the same size. An average value therefore does not mean that each passage in the ceramic has an identical diameter.
Measuring methods such as porosimetry can be used to characterize pore distribution. These measurements describe the structure of the material, but they are not sufficient to demonstrate, on their own, the reduction of a specific contaminant.
To establish filtration performance, specific tests must be carried out with the contaminant concerned and on the complete filter under normal conditions of use.
9. NSF certification and laboratory testing
The Coldstream FTO+ filter, reference CF163W, should not be represented as an NSF certified filter. As of the date of our verification, this reference does not appear in the official directory of certified products accessible on NSF.org for reduction claims according to standards NSF/ANSI 42, NSF/ANSI 53 or the NSF P231 protocol.
The company KLT Filtration, which markets the Coldstream brand, has a listing in the NSF directory for another cartridge, reference CF102W. This registration relates only to compliance with material requirements. It therefore constitutes neither certification of the FTO+ CF163W filter nor validation by NSF of its contaminant reduction performance.
The performance sheet published for the CF163W filter nevertheless indicates that tests were carried out by Envirotek Inc. according to standards NSF/ANSI 42, NSF/ANSI 53 and the NSF P231 protocol. It also mentions references and identifiers linked to the laboratory's accreditations, including an IAPMO identifier.
Testing by a third-party laboratory using NSF protocols does not mean that the product is NSF certified. Certification notably involves official registration of the product, a precise scope of certified performance and monitoring according to the rules of the certifying body.
The published results only document the performances measured under the precise test conditions: reference of the system tested, number of filters installed, contaminant studied, initial concentration, concentration after filtration, volume filtered, flow rate and protocol applied.
The correct wording is therefore:
“Filter tested by a third-party laboratory according to certain NSF/ANSI protocols”
and no:
“NSF certified filter”.
Coldstream FTO+ Filter FAQ
Does the FTO+ filter remove all contaminants?
No. No filter should be presented as effective against all contaminants. You must consult the test results corresponding to each substance sought.
Does an electron microscope analysis prove the effectiveness of the filter?
No. It can provide information on the structure or surface of the material, but it does not replace a reduction test carried out with a specific contaminant.
Does the average pore size allow us to know all the performances?
No. Pore size provides information on the structure of the ceramic, but performance also depends on the water path, the internal media, the flow rate and the properties of the contaminant.
Can the filter be used with non-potable water?
Its use should depend on water analysis and documented filter performance. It should not be assumed that water becomes drinkable just because it has passed through a gravity filter.
When should the filter be replaced?
The time or volume limit indicated in the applicable product documentation must be respected. Early replacement is necessary in the event of cracking, delamination, deterioration or abnormal decline in performance.
Conclusion
The Coldstream FTO+ is a filter combining a ceramic envelope and internal filter media. It can help reduce certain contaminants and improve certain water characteristics, but only within the limits demonstrated by the tests corresponding to this reference.
A reliable presentation should avoid expressions like “exceptional effectiveness”, “revolutionary technology”, “complete protection” or “perfectly safe water”. The commercial information must specify the contaminants tested, the results measured, the configuration of the system used, the test volume and the limits of use of the filter.
