Hippo 7 Water Cistern Bag Water-Saving Flush Displacement Device

Lower your water bills and reduce environmental impact with zero plumbing required.

Toilet flushing accounts for roughly 30% of average daily water consumption across UK households and workplace facilities. The Hippo 7 Water Cistern Bag provides a quick, cost-effective way to reduce waste in slimline, traditional, or larger cisterns. Recognised by Ofwat as recommended good practice with specifically attributable water savings.

By retaining water inside the bag every time you flush, the Hippo 7 reduces water throughput without compromising flush performance. Designed for homes with metered supplies, office buildings, schools, and hospitality venues, this simple device cuts utility charges associated with water processing.

Hippo 9 is for larger cisterns (9 litres and over) saves 2-3 litres per flush, this Hippo 7 is for smaller cisterns (6 litres and over) saves 1-2 litres per flush. 

Key Features & Benefits

• Measurable Bill Savings: For metered UK properties, reducing flush volume directly lowers both incoming water and outgoing sewerage charges.

• Save Up to 2 Litres Per Flush: Specifically engineered for slimline 6-litre (Hippo 7) up to standard 9-litre cisterns (Hippo 9).

• Quick 60-Second Installation: Requires no tools, fixings, or plumbing expertise. Simply open the bag into a box shape and slide it into the cistern.

• Anti-Stagnation Relief Valve: Features a specialised circulation hole allowing controlled water movement so water inside the bag stays fresh.

• UK-Made & Eco-Accredited: Waterwise recommended and manufactured in the UK from a minimum of 30% recyclable heavy-duty polyethylene. The bag can be recycled if no longer required too. 

Product Specifications

Simple 3-Step Installation

1. Shape: Lift the cistern lid and pop open the Hippo 7 bag so it forms a rigid box shape.

2. Position: Place the bag inside the cistern directly beneath the large water float valve.

3. Save: Replace the cistern lid. The bag fills automatically, trapping up to 2 litres of water for every subsequent flush.