Water Filtration
Single-Layer Filters
Single-layer sand filters consist of a single filtering bed, generally made of sand with a nominal grain size between 0.4 and 0.9 mm.
A sand underbed with a larger grain size may be used to protect the diffusers or plates located at the bottom of the filter.
In a single-layer system, impurities are mainly concentrated in the first 10–15 cm of the filter media. This may require more frequent backwashing to restore the filter’s proper efficiency.
This system can reach a filtration capacity of approximately 30 microns. To achieve high water quality, it may be necessary to use flocculants and maintain a filtration speed suitable for the system’s specifications.
Multi-layer Sand Filters
Multi-layer sand filters are composed of multiple layers of filtering minerals, differing in grain size and specific gravity, supported by a gravel underbed that protects the diffusion elements.
The layers are arranged to distribute impurities throughout the entire height of the filter media, limiting accumulation on the surface.
This configuration allows you to:
- Reach a filtration capacity of up to approximately 5 microns;
- Promote the removal of turbidity and suspended solids;
- Reduce rapid surface clogging of the filter media;
- Decrease water consumption during backwashing;
- Limit or avoid the use of flocculants, depending on the system’s conditions.
The filtration speed can reach 50 m/h, depending on the filter and the technical characteristics of the plant.
Diatomaceous Earth (DE) Filters
Diatomaceous Earth filters use a siliceous fossil flour distributed over the surface of specific filter elements. The thin layer formed this way traps impurities and helps achieve particularly clear and crystalline water.
Thanks to the low filtration speed (generally between 5 and 6 m/h), this system can reach a filtering capacity of approximately 0.5–1 micron, typically without requiring the use of flocculants.
Furthermore, cleaning the filter generally results in lower water consumption compared to a traditional sand filter.
Which filter should you choose?
Every system has different characteristics in terms of filtration capacity, maintenance, consumption, and usage. The choice must be made by considering the pool size, the system’s flow rate, and the desired water quality.
Tecnoacque can help you identify the most suitable filtration system and correctly size every component of your plant.
