Stages of purification
The number of purification stages provided for in the filter design. At each stage, water passes through its own filter element, clearing itself of certain contaminants; in this case, the steps are arranged in order from coarser cleaning to finer. For example,
a three-stage system may look like this: the first stage is mechanical removal of impurities, the second stage is the removal of ferrous, and the third is filtration through a carbon cartridge.
The more stages of purification — the more advanced the filter is considered, the cleaner water it usually provides at the outlet. Accordingly, this moment largely depends on the purpose (see “Type”): for example, multi-stage filtration is quite rare in main models, it is practically not used at all in pre-filters, but the number of stages can reach 9 in models for sink.
Cartridge size
The cartridge size indicates both the overall dimensions of the device and compatibility with non-native accessories from other manufacturers. Cartridges differ in width and height, measured in inches. Among the most common options are
5SL (5"x2.5"),
10SL (10"x2.5"),
20SL (20"x2.5"),
10BB (10"x4.5"),
20BB (20"x4.5").
Standard sizes also include
inline cartridges in the form of modules made from white or transparent plastic. They are a sealed cylinder with pre-installed inlet and outlet fittings. Inline cartridges are connected via threaded connections or fittings, simplifying the replacement process. They do not require a separate housing for installation, as their design allows for direct connection to the pipeline or filtration system. They are also slimmer than traditional filters, making a filter with inline cartridges quite presentable in appearance.
Some water purification systems have cartridges in
proprietary sizes that are only compatible with specific filters. These cartridges are ideal for these systems, providing high purification efficiency. They often combine several filtration stages in one element (e.g., mechanical cleaning, chlorine removal, mineralization). This simplifies system maintenance and improve
...s water quality. Proprietary products undergo strict quality control and are tested for compatibility with specific filtering systems, ensuring stable performance. However, there are drawbacks—proprietary cartridges are more expensive and their range is much smaller than universal ones.Replacement cartridges
Models of replaceable cartridges for which the filter is designed. Knowing the names of models, it will be much easier for you to find a replacement for an exhausted cartridge. In addition, the options directly named by the manufacturer are fully compatible with the filter and correspond to official specifications, while there is no such guarantee for "non-native" cartridges.
Several names in this paragraph are usually indicated for filters with multi-stage filtration (see "Stages of purification") — a cartridge for each stage.