Filtration - Backwash

05 March 2015


We should do a backwash once a week, after vacuuming and when the filter gauge exceeds 5 pounds of pressure at its normal operating pressure (around 20).


To clean dirt from the sand filter.


  1. Turn off pump
  2. Put filter handle to the "Backwash" position
  3. Turn on pump for 2 to 3 minutes depending on pool dirt level
  4. Turn off pump for 30 seconds
  5. Put filter handle to the "Rinse" position
  6. Turn on pump for 30 seconds
  7. Turn off pump for 30 seconds
  8. Put filter handle to the "Filter" position
  9. Turn on pump and resume normal use of pool

Filter Positions

Normal position during operation of system. It allows you to filter water through the sand. The pressure gauge should be between 10-20 psi depending on the facilities.

The direction of the water is reversed. The water coming from pump will go through valve backwards, entering the tank at the bottom, and flushing out the dirt and debris that has been trapped in the sand bed. Check the clear window to verify if sand is cleaned.

Position that eliminates pending waste or debris after backwashing sand filters.   The water flow is similar to that of backwashing. It allows the sand to get back into place in your filter.

Position which lowers the water level in the pool without going through the sand filtration. The water flows only in the filter head and does not damage the sand.

Recirculate or Whirlpool:
This position allows water from pump to completely bypass filter and return to pool. Use this position when you drop your chlorine powder directly into the skimmer.

Closed or Winterize:
Position used for winterizing the filter. Leaving your handle between two positions is also another option if you don’t have a winterize setting.

It is recommended to change the sand of you filter every 3 years for above-ground pools and every 5 years for in-ground pools. Turn pump off between each position change.

Pressure gauge reads 0

  • Check the pump impeller and remove debris if necessary with long nose pliers
  • Check the skimmer and remove debris from basket and under basket
  • Make sure the water valves (main drain and skimmer) are open
  • Make sure the O-ring rubbers under the lid are clean and in its proper position. This will allow a good seal.
  • Verify there is enough water in the pump basket
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