Importance of Filtration
The Critical Importance of Filtration
Filtration filters out the micro-organisms, dirt and bacteria feeding particles that cause algae and other forms of bacterial growth, resulting in clearer and healthier water. The most common filters that are used in swimming pools are sand filters and cartridge filters
The Sand Filter
The oldest and most commonly used method of filtration, a Sand Filter is a tank-shaped filter that utilizes a special grade of sand, as a filter media.
While not considered the most effective of filter systems available, results can be improved through regular maintenance and the periodic use of water clarifying products.
A common mistake with Sand Filters is backwashing too often. The reading on the sand filter’s gauge indicates the effectiveness of filtration and helps to identify when backwashing is required. Consult your manufacturer’s instructions to optimize this system.
Also, incorrect operation of the position valve can lead to mechanical failure of the valve around the seal. In addition this can lead to the valve breaking or render it unable to securely hold the position required for the operation in process.
How a Sand Filter Works
With a Sand filter water is filtered from top to bottom. Inside, a special filter sand (called silica sand), which has sharp edges that separate and trap particles, causes filtration to take place.
Water is moved in two directions through this filter system. On the filtration cycle the water comes in through the top and filters down through the sand into the multi-lateral under-drain assembly. On the backwash cycle the water runs down and out this assembly forcing the contaminates and debris out of the sand enabling them to be flushed out of the system.
The 6 Valve Settings of a typical Sand Filter:
1. Filter / Filtration
3. Drain / Waste
4. Whirlpool / Circulation
Tips for Sand Filter Usage
1. Always turn off the pump before changing positions on the valve to release pressure.
2. After replacing sand ensure that the valve is reaffixed in the appropriate position.
3. Always do a complete full turn to protect the seal.
4. When using the drain or waste position, always fill the pool as high as possible.
5. The whirlpool setting is best for mixing chemicals into the water quickly without filtering, such as floc treatment or phosphate treatment.
6. Backwash when your filter gauge has increased from its normal running pressure by 50% i.e. if your normal running pressure is 10 psi, backwash once your filter gauge reaches 15 psi
7. Backwash until the water in the eyeglass is clear or until water at end of the drain is clears. It is recommended to follow the manufactures directions using the filter gauge. Each backwash should be followed with a rinse for 30 seconds.
8. A Sand Filter should be cleaned using a filter cleanerin the spring, Mid-Summer and fall for best filtration results.
The Cartridge filter
A Cartridge filter is a type of filter that utilizes a porous, pleated component to remove particles. Cartridge Filters are very commonly used in spas and more so now on most new swimming pool installs. This type of filter should be chemically cleaned on a regular basis allowed to dry completely before installation to maintain performance. Cleaning twice a season for most average size pools is recommended.
Cartridge filters can also save significant amounts of water loss due to backwashing and also chemicals usage saving money and helping the environment.
How to clean a Cartridge filter:
1. Dilute 250 ML of Clean in a bucket containing 5 L of warm water or recommended amounts with larger filters
2. Put cartridge in bucket; keep it upright until it is covered with solution and let it sit this way for 5 to 6 hours.
3. Immediately rinse the cartridge with cold water or let it soak in a bucket of clean water.
4. Clean cartridge after every second rinsing