Frequently Asked Questions

What type of filter is best suited for my pool?

The choice between a sand filter and a cartridge filter depends on the size of your pool, your maintenance needs, and your budget. Sand filters are more suitable for large pools or frequent use, while cartridge filters are often chosen for smaller pools or those who prefer finer filtration. Additionally, cartridge filters consume less water for maintenance, as there is no need for a "backwash," unlike sand filters. This can be an ecological and economical advantage if you want to limit your water consumption.

How does a sand filter work?

A sand filter works by circulating pool water through a bed of sand. At Trévi, we use filtration glass. Impurities and particles are trapped by the sand as the water passes through, which helps clean the water efficiently. The filtration rate is 20 to 40 microns of particle retention. This type of filter is particularly suitable for above-ground or in-ground pools.

Maintaining the sand filter:

It is recommended to perform a backwash (reverse flow cleaning) every 1 to 2 weeks, depending on pool usage, to maintain optimal filtration. If you notice a significant increase in filter pressure, it's a sign that a backwash is needed. It is also recommended to replace the filtration glass every 5 to 7 years, depending on usage and water quality.

Filter Positions:

• Filtration: This is the normal position for filtering the water. The water circulates through the sand (or filtration glass), and impurities are trapped.
• Recirculation: This position allows water to circulate without filtering it. Useful for certain maintenance steps.
• Rinse: After a backwash, this position is used to rinse the sand and remove any remaining impurities in the filter. (30 seconds)
• Winter: This position isolates the filter for winter, without circulating the water. Ideal for system maintenance during the cold season.
• Close: This position stops the flow of water. It is used during maintenance to empty the pump basket or for other actions.
• Backwash: This position circulates the water in reverse to clean the sand by flushing out accumulated dirt. (2 minutes)

Before handling your filter, be sure to turn off the pump to avoid damaging the filter head.

Why choose sand or filtration glass for my pool sand filter?

Both sand and filtration glass are popular options for pool sand filters, but each has distinct features:

• Sand is the traditional, widely used, and more economical option. It is effective at removing larger impurities from the water and needs to be replaced every 3 to 5 years. However, over time, it may lose its effectiveness due to the accumulation of fine particles, which can make maintenance a bit more demanding.

• Filtration glass provides finer filtration than sand, capturing smaller particles and improving water quality. Additionally, glass lasts longer (5 to 7 years) and requires less backwashing, which helps save water and reduce long-term maintenance costs. Its increased efficiency keeps the water even cleaner, making it a great option if you're looking for optimal and more durable filtration.

At Trévi, we only use filtration glass.

How to install a pool filter?

Installing a pool filter can vary depending on the model, but generally, you simply need to place it near the pool. Then, connect the pipes to your equipment: connect the pump outlet (motor) to the filter inlet, and the filter outlet to the pool's return water or another device such as a heat pump. A small tip: plan for an extra hose for backwashing. This way, you won’t have to disconnect and reconnect the hose every time you use it.

For more information on this process, don’t hesitate to contact us.

How to change the sand in my pool filter?

To change the sand, start by turning off the system and closing the valves to isolate the filter. Then, drain the water from the filter. Remove the filter head and remove the old sand (ideally using a vacuum). Don’t forget to clean the inside of the filter before adding new sand. Add a bit of water (about 1 foot) into the filter and make sure the lateral (spider) is properly positioned before adding the sand. The amount of sand needed depends on your filter model. To know the number of bags, consult the filter’s nameplate or the user manual. Generally, you’ll need between 4 and 6 bags, but this can vary.

Tip: Before adding the sand, check that the lateral (spider) is in good condition and that there is no sand left inside. This will prevent filtration issues and ensure optimal filter operation.

For more information on this process, don’t hesitate to contact us.