How to Clean a Sand Filter
Sand filters are generally thought of as the most compact and affordable way to go when you are looking for a good filter for your pool, be it in-ground or above ground.
Essentially, a sand filter works by running the water of your pool through rough shaped filter sand. This sand removes any dirt or debris that passes through your filtration system and then returns the cleaned water back to your pool.
Over time, this dirt and debris can accumulate in the sand, reducing the flow of water through your filter and causing the pressure to rise above normal. When that happens, the time has come for you to clean the sand filter to remove that excess dirt and debris. To remove any of the excess contaminants, you must backwash your sand filter.
When to Clean Your Filter
There is no hard and fast rule about when you must clean your sand filter . Instead, you need to look at your pool and your filter on a regular basis to determine if it is time for a thorough cleaning.
In most cases, if the sand filter is clogged with dirt and debris the water flow into your pool will be lower causing the pressure to rise on the filter. If your sand filter has both an inlet and outlet pressure gauge, the pressure differential will be low at around 3 to 5 psi when it is clean.
If the pressure rises to between 16 and 20 psi, the time has come to clean the filter. If your sand filter only has an inlet pressure gauge, the filter should be backwashed when the pressure rises by 8 to 10 psi.
Still, you may find that you want to clean it before it reaches these pressure levels. Sometimes, your sand filter can become dirty causing your water to be somewhat cloudy. When this happens and you can’t seem to get the cloudiness under control, your sand filter could be the guilty party.
What Can Clog a Sand Filter
Typically what you will find in a sand filter that has been running for some time are contaminants such as leaves, dirt, and algae. However, there can be other types of contaminants that will clog your sand filter.
If you have a big pool party, for example, the added swimmers can add even more contaminants to the water and shorten the cycle between cleanings. If you are a new pool owner, sometimes material from the new pool such as plaster can quickly gum up the filter requiring you to clean it more often in the beginning of your pool’s life.
How to Backwash the Sand Filter
Backwashing a sand filter is a relatively easy process that is done by simply reversing the flow of water back through the filter in the opposite direction sending the dirty water to waste.
1. Turn off the pump
To prevent damage to any of the plumbing or valves on your filtration system, turn off the pool pump. For added safety, go ahead and turn the power off at the circuit breaker to the pump.
2. Pool Filter Valve
Your pool filter valve is most likely set on the FILTER setting for normal operation. Move the filter valve to the BACKWASH setting.
3. Waste Hose
Lay out your waste hose and run it where you want the waste water to go.
4. Sight Glass
Turn the power on and run the pool pump for at least 2 minutes. Check the water in the sight glass valve. During this process it should change from cloudy to clear. After this time has passed and the water is clear, turn the pump off and switch off the power.
Turn the filter valve to the RINSE setting. After backwashing, the filter sand will be loose and will need resetting and any dirty water that remains from backwashing must be rinsed out of the filter so it doesn’t return to the pool. Turn the pump back on and allow the filter to run on this setting for 1 or 2 minutes.
Turn the pump off and resent the valve back to the FILTER setting. Once complete, turn on the pool pump. Check your pressure gauge to be sure it has returned to normal.
Sand filters are perfect filters for almost any type of pool, although they do require a bit of maintenance in order to keep them running all summer long. This maintenance is easy to do, however, and should become part of your regular pool maintenance schedule.
Remember, always keep an eye on the pressure in your filter and if it gets too high, go ahead and clean your sand filter. A clean filter is key to a clean pool and will help you maintain the highest water quality possible so you can enjoy your pool whenever you feel like cooling off during the summer.
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