Understanding How Your Swimming Pool Sand Filter Works
For easy understanding, it is important to know that your pool's sand filter has a valve that carries out various tasks. For example, if you set the valve to filter mode, water will be directed to the top of the filter where it will flow through sand to trap debris. The sand is compressed and flattened and contaminants trapped. The water will then flow to the bottom of the filter and out through the laterals to the pool. The laterals are extension bars found at the bottom of the filter where you will see a star-shaped section.
Most of the time, the valve is set to filter mode. What are the other modes and functions of this valve?
Backwash Mode
Remember that you have to keep your filter clean. This is the mode responsible for that function. How will you know it is time to backwash? You will need to check the pressure gauge. If it rises above 90Kpa, it is time for backwash. As this rate may differ for different pumps, ask your pool technician. For most pool owners, the optimum pressure range may lie between 50-90Kpa others 100Kpa. During backwash, the direction of water flow is reversed from the laterals to the tank. This causes the sand to decompress and release debris into the water, which then flows out through the waste line.
Rinse Mode
This is done after backwash to reduce the chance of contaminants flowing back to the pool. The process resembles that of the filter, but in this case, water flows out to the waste line instead of going back to the pool. This mode also helps to reseat the sand back to its compressed and flattened state.
Recirculate Mode
This is the mode used when you want to clean and treat your pool using pool cleaning chemicals. Note that you don't want the filter trapping chemicals and reducing their effect in cleaning the pool. Additionally, these chemicals are pricey, and you do not want to waste them. When set to recirculate mode, water will flow through the valve and into the pool without passing through the filter.
Waste Mode
This mode is suitable for when you want to vacuum your pool maybe after a particular treatment, add new sand or during filter start-ups. Water is sent directly to the waste line bypassing the filter.
Winter Mode
During or before winter, pools, filters and pumps get drained. The winter mode helps in separating the internal valve parts to prevent them from freezing.
If you have more questions, contact local services such as Leisure Coast Pool Centre.
