The sand in the filter should be changed every 5 - 6 years.
Before if you have problems keeping the water clear, anytime, especially after a shock treatment. The quantity of sand required is at the bottom left on the label for most models.
Once you have the required amount of 50lb bags of sand:
- Stop the pump
- Drain the filter
- Remove the filter head and empty the tank with a shop-vac or ladle
Once empty**, lift carefully the lateral assembly so you can reach and remove the laterals, turning counter clockwise about a quarter turn. (If your filter is a more recent Hayward model, the laterals fold upwards like an umbrella). Take it out and examine it.
If a new lateral assembly is required, take all the broken parts with you, as the total length is needed to get the right model.
The lateral assembly is placed back in the middle with the laterals outretched. Place a glass upside-down over the top of the assembly to ensure that no sand goes into it.
Fill the filter tank with sand up to its shoulders.
Put the filter head back, making sure that the lateral assembly end and the one from the head fit into each other.
Put the handle on backwash for about 1 minute to make sure that the dust will not be coming back into the pool, once you restart the pump.
**USE THE OLD SAND IN THE WINTER WHEN YOUR DRIVEWAY AND STEPS ARE ICY. SCATTER SOME FILTRATION SAND (NO DAMMAGE LIKE CALCIUM OR SALT). WHEN THE ICE HAS MELTED AND IT'S DRY, SWEEP IT BACK IN THE BAG FOR THE NEXT TIME, BECAUSE IT'S REUSABLE!