Carat Tank Capacity's

Submersible Pump Submersible Pump Submersible Pump Submersible Pump Submersible Pump

Graf Optimax-Pro Self Cleaning Filter

Calmed Inlet prevents sediment from being stirred up keeping water clean and clear

25 meters of 25mm HDPE rainwater pipe included as specified by all waterboards

Overflow Siphon stops odours when connected to a soak away or mains sewer

HydroForce™ Series 3 submersible pump

Carat Tank Garden System

Our Garden system is an easy and cost effective solution offering rainwater for 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.


  • Harvested rainwater is exempt from hosepipe bans, providing drought protection for your plants.
  • HydroForce™ pump delivers 3.5 bar- enough to run high pressure sprinklers and pressure washers.
  • High quality self cleaning filter.
  • Everything included to run a full system.

Tank 2700 Litres 3750 Litres 4800 Litres 6500 Litres
Product Code 370001 370001 370003 370004
Weight 120 kg 150 kg 185 kg 220kg
Length 2080mm 2280mm 2280mm 2390mm
Width 1565mm 1755mm 1985mm 2190mm
Height 1400mm 1590mm 1820mm 2100mm
Total Height 2010mm 2200mm 2430mmm 2710mm
Half Height (before assembly) 700mm 790mm 910mmm 1050mm

RainWaterHarvesting Ltd is the UK’s largest stockist of Rainwater Harvesting tanks and as such can offer competitive prices for trade and commercial sales.

RainWaterHarvesting Ltd are also experienced in dealing with multi-dwelling and housing developments requiring multiple installation of rainwater harvesting tanks, and can give advice on meeting required Code levels, planning stipulations and flood attenuation issues.

Call us now on 01733 405111 for more information, or visit our store