Pumps, filters and equipment
Replacing the sand in a pool filter
Filter sand wears out. Old, clumped sand lets fine dirt through and makes a pool harder to keep clear, however good the chemistry.
New filter sand has sharp, angular grains that trap fine particles. Over the years the grains round off, oils from sunscreen and body products coat them, and calcium from hard water cements patches together. Water then carves channels through the bed and passes through without being filtered properly. Owners notice water that stays dull despite good test results, or pressure that climbs again soon after a backwash.
Equipment guides cover servicing and faults on the plant an existing pool already has.
Replacing the sand means switching off and isolating the system, draining the filter, removing the old media, inspecting the internal laterals and central standpipe, and refilling with the grade and quantity of media the filter is designed for. The system is then backwashed and rinsed before normal running. Cracked laterals found while the tank is empty are replaced at the same time.
The short version
Worn grains filter less
Rounded, coated sand lets fine particles pass straight through.
Clumps and channels
Water follows the easiest path through a cemented bed.
Inspect the internals while open
Laterals and the standpipe are checked during every media change.
Signs the media is due
Short runs between backwashes
Pressure rises again quickly, often because the bed is clogged deep down.
Persistent dull water
Clarity does not improve despite balanced chemistry and long run times.
Sand appearing in the pool
This usually means a broken lateral rather than old sand, and is investigated separately.
Before the change
Read the filter label
It states the media type and quantity the tank was designed for.
Ask about alternative media
Some filters can take glass or other media; the manufacturer’s guidance decides.
Plan a short downtime
The pool is without filtration while the media is changed, so avoid doing it during heavy use.
Common questions
How often should filter sand be changed?
It depends on use, water hardness and how well the filter has been maintained. Performance is a better guide than the calendar.
Can I just top up the sand?
Topping up rarely restores performance. The whole bed is normally replaced.
What are laterals?
Slotted arms at the bottom of the tank that let water out while holding the media in.
Related pool care guides
- Cleaning a pool cartridge filterA related check on the same part of the plant.
- Filter sand returning to the poolA related check on the same part of the plant.
- Backwashing a sand filterA routine task that prevents the same trouble.
- When pool pH is too highAnother water problem with a related cause.
This guide sits under pump & filter services. Browse all pool care guides. We look after pools at homes and commercial properties across Dubai.
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Next step
Filter not keeping the water clear?
Tell us your filter model and how often you backwash. We will check whether the media needs changing.