This is the normal operating position of the filter. In this stage or position, untreated water flows through the inlet side of the control valve and down through a “captured” dome of air which oxidizes and precipitates iron and or sulfur. As the water flows through the media these precipitated contaminates are filtered by the media. It is at this moment the undesirable minerals are removed from the water.
This is the first position in the regeneration sequence. In this position(s) the valve goes through a series of vary small movements (“inching along”) allowing the “captured” dome of air to release slowly and more importantly, harmlessly down the drain. This patented feature allows for the filter to expel the pressurized excess air without the violence associated with other air systems.
Backwash is a step in the regeneration process where the media in the tank is physically lifted up, spun around and agitated under pressure. It is cleaned of any particles such as precipitated iron or sulfur which has been filtered out during normal use of the system. The backwash water containing the undesirable particles flow harmlessly to drain.
It is this position in which we draw in the air into the tank replenishing the air charge. This is needed to replenish the air which is consumed in the oxidation and precipitation process in the normal service position. Some units have the option of using an ozone generator during this position to ensure additional oxidation and bacteria control.
This is really not a position but rather a process. As the valve returns to the service position the inlet port is open to the tank, this allows water to fill the tank from the bottom to the top. As the tank fills, this compresses the dome of air in the top portion of the tank, it is this air (optional ozone) that is used in the oxidizing process of the service run.