What is Backwashing and How Does it Help your Pool?

Swimming pool owners know how much maintenance is needed to keep pool water sanitized and clear. This includes ensuring that the pool is chemically balanced and scrubbing, vacuuming, and backwashing, among other things. What is backwashing though and how does it help your pool? Backwashing has something to do with the filter system and the sand that is inside it. The sand itself blocks debris, oil, and dirt making it an important component of your filter.

A regular filter works well during the first few months especially for pools that do not get a lot of debris but after some time, the sand will need some washing. This is where the six different filter mechanisms come in. This includes filter, backwash, rinse, closed, waste, and circulate.

Backwashing and Why you Should Do it Regularly

Backwashing is defined as the reversal of water flow in a pool. Doing this will help get rid of build up in the filter system making it more efficient in the days to come. As more dirt goes into the filter bed, it is expected that flow would decrease. As a result, water discharge into the pool also decreases. Concentrated levels of debris accumulated by the sand inside the filter reduce the sand’s capability to filter the water in your pool. When this happens, all that dirt and debris will go right back into your pool making it dirty. Backwashing prevents this from happening because the mechanism lifts up the sand and expels dirty water into the waste line or the drain.

Backwashing also helps kill algae bloom and can also help you treat cloudy water. Our experts recommend that you only add chemicals to your pool after properly backwashing it.

How to Backwash a Sand Filter

  1. Turn off the pump.
  2. Get the valve into the backwash position.
  3. Turn the pump on.
  4. Let the water flow until the water is clear. Do this for approximately 2-4 minutes.
  5. Turn off the pump and put the control valve into the rinse position.
  6. Turn the pump on again for 30 seconds.
  7. Turn the pump off again and set it to filter.

How often should you backwash?

Backwashing and rinsing your filter should be done every week right after vacuuming the pool. However, during busy days when the pool is getting used more than usual, you would need to backwash two times a week. It is important to take note of the debris that gets in your pool so that you know when to increase backwashing frequency.

If you want to make sure that it is really time for a backwash, you can check the pressure gauge of the filter system. Normal pressures fall between 50 kilopascal to 75 kilopascal. If it rises above 75, it means it is time for a backwash.

Will there be times when backwashing is not the right option?

Pools that are often dirty need to be cleaned without the help of the filter especially if the pool has been untended for a long time. While you can backwash to get rid of algal bloom, it is not a good idea if the infestation is already too much. This is because live algae will only re-enter the pool due to the inability of the sand filter to block them. Cases like these can happen from time to time and when it happens, vacuum your pool directly to the waste mechanism. This will send the water right down the drain.

Backwashing Notes

  • Backwashing wastes a lot of water. To avoid wasting too much of this resource, you have to keep an eye on the water quality by looking at the sight glass.
  • Try not to overdo it. If you don’t need to backwash, don’t. Overdoing it can affect the sand filter’s efficiency.
  • Remember to add more sand into the filter when needed.