The length of time you can keep water in a water butt depends on various factors, such as the size and material of the water butt and the quality of the collected rainwater. In general, rainwater stored in a properly maintained water butt can be kept for several weeks to several months. However, it's important to note that rainwater is not treated or purified, and over time, it may become stagnant or develop algae, which can affect its quality.
The quality of the rainwater collected in a water butt can vary depending on factors such as air pollution, debris, and contaminants from the roof or gutters. It's recommended to use a water butt with a built-in filter or add a filter attachment to the downpipe to help minimise debris and contaminants from entering the water butt. Regularly checking and cleaning the water butt, including the filter, can help maintain water quality.
If you use the stored rainwater in your water butt regularly for watering plants or other purposes, the water turnover will be higher, and the water is less likely to stagnate. Using the collected rainwater regularly can help ensure that the water remains fresh and reduces the risk of water quality issues.
Regular maintenance of the water butt is important to ensure the water remains clean and fresh. This includes checking the water butt for debris or sediment build-up, cleaning the container and filter as needed, and ensuring that the tap or hose attachment is in good working condition. Following the manufacturer's instructions for maintenance and cleaning is recommended.
It's generally recommended to use up the stored rainwater in a water butt within a few weeks to a few months to ensure optimal water quality. If you have concerns about water quality or if the water in your water butt appears discoloured, has an odour, or shows signs of contamination, it's best to discard the water and clean the water butt thoroughly before collecting new rainwater.