A slow flow rate means that the top of the sand is plugged with dirt. The dirt should be removed using the swirl & dump maintenance:
- Remove the filter lid.
- If there is no water above the diffuser, add about four litres (one gallon) of water.
- Remove the diffuser.
- Using the palm of your hand, lightly touch the very top of the sand and move your hand in a circular motion; be careful not to mix the top of the sand deeper into the filter.
- Scoop out the dirty water with a small container.
- Dump the dirty water outside the house in a soak pit or garden.
- Make certain the sand is smooth and level.
- Replace the diffuser.
- Wash your hands with soap and water.
- Set up the storage container to collect the filtered water.
- Refill the filter.
- Repeat the swirl and dump steps until the flow rate has been restored.
The biolayer has been disturbed by the swirl & dump, but it will develop again over time. It is recommended to disinfect the filtered water during this time.
