Filtration & Circulation /
How to Change Sand in a Pool Filter
To change sand in a pool filter, shut off the pump, relieve pressure, open the tank, remove the old media, inspect the internals, and refill to the manual’s level.
Archive date: this article was written for PoolSkimmer on Oct 23, 2026 and given the earlier archive date of Sep 27, 2026 so the blog reads as an organized archive. It was not published on that date.
Replacing the sand in your pool filter
There is no set rule for when to put in new sand; it is a matter of the manufacturer’s guidance, water conditions and the model of the filter. You will know it is time for a change if backwashing fails to put you back in the clear or restore a normal flow. This can be an indication the sand has become compacted, worn out or is channeling around debris.
Some of the more common signs are: - Water that turns cloudy again shortly after you have cleaned it - A return flow that is weak despite the system running as it should - The need to backwash often with nothing to show for it - Sand making its way back into the pool - Filter media that has seen many seasons of service
Precautions before opening the filter
Safety comes first. Before handling the skimmer or strainer basket, or the filter itself, make sure the pump is off and power to the system is cut. Under no circumstances should one open a tank while it is under pressure. Put on some PPE in the form of gloves and eye protection and refer to the owner’s manual on how to relieve pressure.
A few things to do prior to starting: - Make certain the pump has no chance of an unexpected restart - Follow the manual to the letter when relieving pressure - Have the proper replacement sand on hand for your particular model - Set aside a clean spot for the old parts and media
And never put your hands in any suction openings or work on equipment that is still operating.
A step by step guide
While the process is much the same for most pool filters, the manual should be your first reference. A safe approach would be to:
1. Cut the power and turn off the pump. 2. Let the pressure out of the filter as directed. 3. Open the tank with care. 4. Take out the old sand, being careful not to harm the standpipe or lateral assembly. 5. Look over the valve parts, seals, laterals and the tank for any clogging, wear or cracks. 6. Put back in place anything you had to remove to get access. 7. Slowly add the new sand, sticking to the type and fill level called for. 8. Seal up the filter and check for leaks before you start the system up.
Do not leave the fill level to chance. Too much and performance suffers, too little and the filtration will be poor. If there is a top-mounted valve or some other internal configuration, the manual is all the more important.
Where problems tend to arise
The sand is not hard to replace, but mistakes during disassembly and reassembly are where most trouble comes from. Be on the lookout for using the wrong amount or kind of media, or breaking a lateral in the process of removal. It is also easy to overlook a crack in the head or tank, or to fail to properly reseat a gasket or O-ring. And do not restart the pump until the job is fully sealed and put together.
For models like Hayward, the equipment instructions take precedence over any general advice.
Time to call in a pro?
If you have a cracked tank, a broken lateral, a leaking valve or cannot depressurize the unit in a safe manner, put in a call to a qualified professional. The same goes if the plumbing is unyielding, the filter is of a large size, or you think a damaged part inside is to blame for the sand issue.
Should you come across an electrical fault, stop using the equipment and have it serviced. Proper operation and maintenance are what make for safe filtration, so do not swim until the matter is resolved.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)