The fact that the filter can not always clean the water, and there comes a time when it becomes clogged. Need to replace the cartridge in the purifier. So, first turn off the water to the filter. Complete with filter must go on the tap. With it, you need to Unscrew the bottom part of the filter.
After this you need to remove the old cartridge. Almost all filters, except those that purify water mechanically, there are at the ends of the cartridge rubber-seals. They definitely need to check it out. If they are soft, elastic, it is possible to take them off, wash and keep for later use. Rubber-seals should not be hard and tight. Otherwise, they must be replaced. If you are unable to find the soft gum, the filter will have to tighten, applying a lot of effort. Tighten gradually.
Then pour them in the bulb remains of the water, rinse the flask with water from the tap. Pre-dial to use the bucket of water. In a clean flask install the new replacement cartridge. Screw the bulb with the key until it stops.
If you change the filter in the reverse osmosis apparatus, wash out the bulb with a new replacement filter is best to fill out a pre-prepared purified water. The point is that the reverse osmosis membrane does not tolerate air bubbles. If you change the usual, not a membrane filter, the air will just go out through the valve.
Further, it is necessary either to replace the following cartridge, or if everything is replaced, gradually try to open the tap. When applying water to the filter is necessary to ensure that it does not leak between the bulb and head of the filter. If water is seeping, you need to turn off the water and tightly screw on the bulb. If that doesn't work, you need to Unscrew the bulb and verify the integrity of the thin rubber ring, which is in the hollow of the bulb. If damage ring must be replaced.