The smallest particle size that the cartridge is capable of retaining; smaller contaminants will be able to penetrate through it. Accordingly, the
smaller the number in this point, the finer the filtering provided by the cartridge. On the other hand, increasing the filtration thoroughness inevitably reduces the performance, other things being equal. So the choice of cartridge is often based on a compromise between thoroughness of cleaning and throughput.
Also note that the choice depends on the purification stage at which the cartridge is planned to be installed. So, at the initial stage, coarse cleaning is used, with clipping impurities at the level of 25 microns or more. Filter elements with an index from 25 to 0.3 microns are classified as fine filters, and lower values are typical for ultra-fine elements, in particular, for osmotic membranes (see "Application").
The filtration rate provided by the cartridge, in other words, its maximum performance (throughput).
This indicator is directly related to the regular use of the cartridge (see above). It is also worth considering here that usually the finer the cleaning, the lower the performance of the filter element. Therefore, for example, flow pre-filter systems at the entrance to an apartment can be performant enough not to slow down the flow, but getting drinking water is inevitably associated with a slowdown in the process. This is especially true for reverse osmosis systems. Filter jugs also do not differ in performance, because they work without pressure. In addition, we note that when installing several filters in series (in a flow system), the final filtration speed will be limited by the speed of the slowest filter.
In general, when choosing a cartridge for a jug, a filter
for a tap or a travel filter, you can not pay much attention to this parameter — performance is usually guaranteed to be enough to work for its intended purpose. Detailed recommendations for other types of filters can be found in special sources.
