Rain water cistern pumps

The ecologically useful source of water in an automated garden irrigation.

The cistern pump is placed directly in the water of the cistern. This allows the rainwater from the cistern to be fed directly into the irrigation system. Rainwater is the best water for watering your garden from an ecological and plant point of view. A cistern pump for rainwater is cost-effective, it not only saves a lot of drinking water but also saves you operating costs for your garden in the process.

Cistern pumps: filtering, floating extraction and filtering again

To ensure that the pump lasts a long time and that no particles from the cistern are carried into the irrigation system, we recommend 3 basic things;

  • Firstly, the rainwater should be filtered thoroughly before it enters the cistern. For this, there are special downspout devices that can purify water very well even while collecting water and filter baskets, that filter the rainwater before it goes into the cistern.
  • Secondly, for garden Irrigation, we recommend cistern pumps that have a threaded inlet spigot. In contrast to flat suction pumps, a floating extraction can be attached to these nozzles.
  • Thirdly, use a floating extraction which consists of a flexible hose, a coarse filter, and a floating ball. This design ensures that the pump draws in water that is just below the water surface so that particles, such as pollen, that float on the surface are not sucked in. Likewise, sediment consisting of fine inorganic material remains in the cistern and is not sucked into the irrigation system.

Never run dry: automatic drinking water replenishment for cistern pumps

Even during longer dry periods, the system should water your garden reliably. If it doesn't rain for a long time and the cistern empties, an automatic drinking water replenishment ensures that there is always enough water in the cistern to start the next watering process. This also protects the cistern pump from running dry. By means of a float switch suspended in the cistern, a solenoid valve opens when the water level is too low and drinking water is fed into the cistern until the float reaches the minimum level that allows irrigation (the cistern will not be filled to ist full capacity)

Design of cistern pumps: how much water, how much pressure?

With the pump, you can read the amount of water available from the characteristic curve. Often, the manufacturer's specifications are somewhat misleading; if, for example, 5 bar maximum pressure is specified for a pump, then this pressure is only available at 0 l/h withdrawal rate; as soon as water is withdrawn, the pressure drops. It is the same with the water quantity, if e.g. a max. flow rate of 5000 l/h is indicated by the manufacturer, then only if no pump height must be overcome. We operate the system at 3.5 bar (35 m pumping height) plus installation depth of the pump. The delivery head of the pump is negligible for shallow cisterns. How to read the characteristic curve of the cistern pump is explained on page 29 in our planning manual.

DVS Beregnung - Submersible pumps for garden irrigation

We offer pumps ready as Plug&Rain® set. The delivery time of the submersible pump is usually a few days. The delivery includes the cable.

With the DVS Irrigation Planner you can plan your automatic garden irrigation online for free. We use 3/4" PE pipes for this. For the pump design we recommend a maximum flow rate of 1.8 m³/h at 3.5 bar for 3/4" pipes. You can plan the pump directly into your project in the DVS Irrigation Planner (step 3 / system elements). It will then be automatically added to the shopping list at the end of the planning process. Together with all other material you need for the installation of your garden Irrigation.