Excess water is drained into the sewage system or an infiltration system via the overflow siphon. Particles floating on the surface are also filtered out of the water in the event of overflows. The siphon ensures that no odours from the sewage system enter the tank.
Watering the garden with rainwater
Gardens like nothing better than rainwater. This natural resource is free and contains no limescale-causing minerals, which makes it particularly good for garden plants.
Once it has passed through the filter, there are only very small particles of dirt left in the rainwater. Over time these sink to the bottom or float to the surface. The steady inflow prevents the sediment at the bottom of the tank from being stirred up.
Carat underground tank
An underground tank forms the very heart of the rainwater harvesting system. Depending on the desired size and installation situation, customers can choose between a traditional Carat underground tank or the Platin flat tank. Here the water is stored under optimum conditions.
The tank cover seals the rainwater harvesting system at the top edge of the ground. For optimum adjustment to local circumstances, its height can be continually adjusted and it can be tilted. It is sealed to the top edge of the ground. Depending on installation site, it can be suitable for pedestrian, vehicle or HGV loading.
A submersible pump with integrated pressure monitor ensures a constant water pressure. It switches on and off automatically.
The rainwater reaches the extraction points via an empty pipe, allowing the rainwater to be conveniently extracted at any time.
Before the rainwater enters the tank, it must be cleaned by a filter. This is essential for the quality of the harvested rainwater. GRAF provides numerous filter systems for very different requirements.