Rainwater Harvesting Limited

Rainwater Harvesting Limited

- Tank Header Tank System



The Graf Carat tank has deservedly led the worldwide market for deep dig tanks for the last five years. Unlike any other tank of its kind, the Graf Carat is assembled from two high strength, injection moulded halves. The advantage of this is the ease to transport due to the manageable weight of the stackable halves.

  • Ideal for large sites with large numbers of tanks delivered simultaneously
  • As the tanks are delivered in manageable halves, the tanks can be delivered to areas with poor access
  • Lower purchase price
  • German made with trusted GRAF name
  • Inclinable lid can be used in sloping areas, allowing up to a 5° tilt.

Our Rain Director Header Tank system is an easy and cost effective solution offering rainwater for domestic use, ideal for flushing toilets and washing machines as well as garden irrigation and other outdoor uses including car washing by simply capturing all of the rainwater from your roof area.

System includes:

  • Graf Carat S Underground Tank, which consists of two halves, meaning multiple tanks can be stacked for ease of shipping. The tank is made from Duralen a high quality and extremely rigid material manufactured by injection compression moulding offering unbeatable stability meaning the tank is groundwater stable up to the middle and comes with a 15 year guarantee.
  • Optimax Pro Internal Self Cleaning Filter is a low maintenance efficient cleaning system providing over 95% water yield and can manage roof areas up to 350m². It has a low offset height of only 165mm between inlet and outlet and comes with transparent lid for easy visibility.
  • HydroForce Series 3 Submersible Pump is a British manufactured twin chamber design with alloy bulkhead, and features a self controlling pressure switch, non return valve and dry run protection. The HydroForce Series 3 can produce up to 3.5 bar of pressure and deliver over 2500 litres per hour with a power usage of 800 watts at 220-240v AC and comes supplied with an inline filter, stainless steel strainer, and a 10 metre cable.
  • Rain Director is the only WRAS approved rainwater management system, designed and built by RainWater Harvesting Ltd this intelligent gravity feed system ensures constant supply of water to all amenities even in the event of a power cut. Pump activity has been reduced due to level sensors within the smart header tank only demanding rainwater when the header tank is almost empty. Auto flush function refreshes water within the header tank to prevent stagnation when system detects a 72 hours period of inactivity. Complies with U.K. Building Regulations by means of an appropriate air gap.


  • Premium domestic system for toilets, washing machines and garden use.
  • Low energy Rain Director header tank system, running costs from 1p per person per day.
  • Automatic mains water backup, in any eventuality- low tank water, pump failure or even power cut.
  • Ultimate control, unique smart features.
  • Everything included to run a full system.

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