Time for a quick hack!
The toilets at HSBNE are decades old and incredibly water-inefficient. The average modern toilet uses only 4.5 litres of water for a full flush & 3L for a half-flush, but our old single-flush-type toilets consume over 10L with only one flushing type. You can lower this value by yourself using mostly household junk!
Conventional advice is to use a brick. This works, but sometimes you don’t have a spare brick handy. Instead, grab an empty 2L plastic milk bottle. Add a little bleach (optional but if you don’t add bleach make sure you never ever open this bottle again once it’s installed because it’ll smell bad). Add some rocks or gravel (something heavier than water). Fill to the very very top with water leaving no air bubbles, then seal it up. Congratulations, you’ve just made a something that’s heavier than water! This is important as you don’t want something that will float around and interfere with the flushing mechanism, it needs to sink to the bottom and stay in position.
‘Two white bottles, hanging on the wall…’
Place this inside the cistern in a position that won’t interfere with the flushing mechanism, and presto! You’ve got yourself a slightly more water-efficient toilet. Not recommended for modern low-flow toilets. Be sure to monitor the toilet’s flushing performance after installation & remove if performance notably decreases.
I’ve installed some of these in HSBNE’s toilets and will be monitoring their effectivity over the coming weeks; all going well I will be installing them in the rest. Because it’s not entirely about saving the environment, it’s really about saving us money.