It’s important that your pool sand filter has the right size. The same way it’s important to have a pump with the correct performance. Only this way, you can guarantee good water quality. In this category you will find the most common filters. You can find cartridge filters and a rather big selection of sand filters for all pool sizes. We have in our assortment the biggest brands in the business: Calplas, Kripsol, Hayward and Welldana. When you choose your next filter, you can find great help by using our Welldana filter-pump and sand filter calculator. We have developed the calculator as an app you can get on your phone/tablet. It can be found on our download area: https://www.welldana.com/downloads/. By using our calculator, you can expect to save money in water, chemicals, and electricity. This way you will get the cleanest water. Better and cheaper.
In a sand filter you can put different kinds of filter-materials but the most common, is sand. There are however alternatives better to use, and cheaper in the long term. Like the AFM filterglass, https://www.welldana.com/afm-aktiveret-glas-filtermedie.html is a filter material that does not need to be replaced. It requires lower waterflow and cleans the water exceptionally better.
The sand filter is in principle just a big container full of sand (or other filter material https://www.welldana.dk/pool/pool-udstyr/filtermedier-og-daisy.html), that filters out the water in your pool. On the sand filter, there is a multiport valve where you can control the functions in the sand filter. The sand filter is mounted in extension of a filter pump. https://www.welldana.com/pool/pool-udstyr/pumper.html. On the sand filter there also must be a manometer. https://www.welldana.dk/manometre.html, who is measuring the pressure in the filter. The multiport valve https://www.welldana.com/multiportventil.html
Important note: The handle must be turned clockwise, and only when the filter pump is shut down.
In this section, we will shortly tell you about the functions of the multiport valve.
- Rinse (after backwash)
Filtration is the main function of the filter. When this function is selected, the water is being pumped down through the filter material. When it reaches the bottom, the water is pumped out of the filter and into the pool. In that way most of the impurities are deposited in the filter. Sand is a really good way to filtrate, because the water will flow through millions of tiny cavities, where the impurities gets stuck. The other filter materials are developed to have more of these cavities, which are smaller than the cavities in sand. When the impurities get into the filter, the filter material will collect the impurities and get dirty. When the filter material gets dirty, the pressure will increase, and it will be harder for the water to pass by the filter. When the pressure increases to 5 PSI (0,35 Bar) over the normal pressure, it is time to do a Backwash.
Every time you turn the handle, remember to shut down the pump. To do a backwash, you must install a backwashing tube https://www.welldana.com/returskylningsslange.html to your filter and turn the handle to Backwash position. Now you can turn the pump on again. With this function, the water will be pumped through the filter, but in a reversed direction. The biggest impurities will lay on the top of the filter material and they will come out quickly. The whole process doesn’t take a long time, but at first, the water will be very dirty. The backwash procedure is finished when the water is clear. Shut down the pump before you turn the handle to Rinse.
Rinse is the step after a backwash. You must rinse the multiport valve after every backwash. This is because some of the impurities will still be in the multiport valve. These will end in the pool if you turn directly to filter position. The rinse time will only take 30 seconds. After that you can shut down the pump and turn the handle to filter position.
This function is used if there is too much water in the pool. It could be because of much rain. Remember to shut down the pump before turning the handle on the multiport valve. When you use the waste function, you must use your backwashing tube. In waste function the water doesn’t come in the filter. The waste function is normally used in the beginning of the season, or if there is a lot of dirt in the pool. This way you ensure that the filter doesn’t get overloaded. It can also be used to get rid of algae after, an algae treatment.
This function is almost exclusively used, when you treat the water with chemicals, you don’t want the filter to pick up. In that way you are maintaining a natura flow in the pool, so the water always is in movement. This is particularly important if you want to treat the water for algae, because algae prefer stagnant water. Alternatively, the recirculate function can be used to check the filter for any errors. An error in the filter, could be sand in the pool. If you are using this function, you will quickly see if there is an error in the filter, because with this function, the water doesn’t come in the filter.
This function is only used when the pump is shut down for cleaning the prefilter basket.