In order for your sand filter to work optimally, it is important to clean the filter sand regularly by Pool cleaning.

After about 5-10 days, or when the reading of the pressure gauge on the pump side of the filter has increased by about 0.2 bars (20 kPa, 3 psi) since the last backwash, backwash the filter as follows:

1. Stop the pump.
2. Close the valves on the suction and return lines.
3. Open the cover of the pump and empty the filter basket.
4. Refit the cover.
5. Open the valve to the drain outlet.
6. Turn the lever to BACKWASH.
7. Open the valves to the suction and return lines.
8. Start the pump. Rinse the filter for about 1 to 2 minutes or until the water in the sight glass is clear. NOTE: Any electric heater must be off.
9. Stop the pump.
10. Turn the lever to RINSE, start the pump and rinse for about 15-30 seconds. Stop the pump and turn the lever to FILTER. This is the normal operating position
11. Close the drain outlet valve and start the pump. Switch on the electric heater if any.

 

Positions of the backwash valve

FILTRATION  – Normal filtering position
BACKWASH  – Cleaning the filter sand
RINSE  – Stabilising the filter sand
WASTE  – For vacuum cleaning the bottom of the pool directly to drain, or for emptying the pool
CLOSED  – Closed
CIRCULATION – Pumping water directly to the pool (no filtering)

Important Backwashing Tips

• The one downside of backwashing is that, because water is expelled from the system and sent into waste, is that it…well…wastes water. While this is unavoidable, the key to not overdoing the backwash process and flushing out more water than strictly necessary is to keep a careful eye on the colour and quality of the water in the sight glass.
• Don’t backwash more than necessary, or for longer than necessary. Sand filter systems operate most efficiently during the middle of the filtration cycle. This is partly due to the positioning, at any given time, of the sand in the filter, and partly because of the cyclical build-up of collected dirt and debris in the filter. The net effect is that too much or as frequent backwashing actually reduces the sand filter’s efficiency.
• Because backwashing inevitably washes out some sand along with the dirt and debris, from time to time it will be necessary to top up the amount of sand in the filter. When you do add extra sand, run the filter system to RINSE for a minute or so to reduce the amount of sand blowback into the pool. We recommend this replacement filter sand here.
• Finally, absolutely make sure you always turn off the pump before you either move or reset the filter valve setting. If you don’t, you’re going to damage, and maybe destroy the system.