The sand filter works with the pool pump, which filters the water before it enters the pool again. The media filter traps dirt, debris and other small particles. That being said, larger pool filters will allow more time while cleaning.

Sand filters are the most compact and affordable option for filtering an in-ground or above-ground pool. Sand filters use a specially designed pool filter sand that removes dirt and impurities when water is pumped through the media. The purified water flows back into the pool. In a sand filter, backwashing occurs when the water flows out through the waste and instead of flowing back into the pool, the filter is cleaned. As the filter sand becomes old and dirty, the water flow pressure through the filter will decrease. This decrease in water flow pressure will increase the pressure rate of the filter. This will tell the pool owner that it's time to wash the back of the device. Generally, sand media should be replaced every five to eight years depending on usage.

Before choosing the right filter for your pool, you must first select the right pump for your pool. Your pool filter should match your pool pump. If the filter is too small compared to the pump. The pump will create more water pressure in the filter than the filter can handle. This imbalance will quickly break down the filtering material of the filter, which will greatly reduce the effectiveness of the filter. In more extreme cases, high pressure buildup can cause cracks in the filter tank and cause it to explode. This guide includes how to properly measure your pool filter.

A common pool circulation rule is to be able to filter all the water in your pool at least once a day. Customers typically have their single speed pump running for 8 hours, so they need a pump/filter system that can recycle their pool water within 8 hours. The first step is to calculate the total amount of water in your pool. For this guide, we will assume a typical in-ground pool size of 100 m³

After receiving the amount of water in your pool (100 m³ for this example), you need to calculate the flow rate (m³/h) required to filter 100 m³ within 8 hours. That is: 100/8 hours equals 12.5 m³/h

As water flows through the system piping between the pool and the pump, the resistance to flow will depend on factors such as the length of the piping, the number of turns (elbows), and the diameter of the piping. This resistance is called the "Feet of Head" or "Head". The higher the head, the lower the actual flow rate of your pool. Calculation of Head can be involved and is generally done during the initial installation of the pool. Most basic in-ground pools have a head of 10 to 15 meters. For this example we will assume 13 m.

Now that you have determined the flow rate required for your pool and its head, you have the information you need to choose the size of the pump for your pool. Go to the Pump Sizing page or the Pump Selection page to find out the style of pump you want to buy.

In the sand filters the maximum filtration speed is normally assumed to be 50 m/h or 50 m³ per hour for every square meter of filter surface area. Sand filters are usually circular and are of 0.5, 0 .6, 0 .75 or 0 .9 m in diameter.

So the required filter area is = The hourly flow rate/50

So with a flow rate of 12.5 m³/h the required filter area is 12.5/50 = 0.25 m²

The sand filter area is (3.14 x d²)/ 4 and so the filter size required is 560 mm or a 0.6 m sand filter.

Therefor in this case the customer need a sand filter with a diameter 0.6 m