5 Ways To Stop Your Water Butt Smelling

Your water butt (rain barrel) can start smelling when things like leaves, algae, bird droppings, etc. decomposes in the water. The smell is usually harmless but unpleasant.

Here are 5 practical ways to stop and prevent the smell:

1. Clean the Water Butt Periodically

If the smell is already strong, start with a good clean.

Empty the water butt completely, making sure all remaining water is drained out. Once it’s empty, scrub the inside thoroughly using a brush, or a broom if the water butt is deep and hard to reach. After scrubbing, rinse it using a mild solution of vinegar or bicarbonate of soda to help remove any residue and keep it clean. Then rinse thoroughly with clean water to ensure no cleaning solution is left behind. Avoid using harsh chemicals like bleach, especially if you plan to use the collected water on plants.

Highlights

Empty the water butt completely.
Scrub inside with a brush or a broom if you have a deep water butt.
Rinse using a mild solution of vinegar or bicarbonate of soda.
Rinse thoroughly with clean water.
Avoid harsh chemicals (like bleach) if you use the water on plants.

2. Fit a Lid and Filter

Smells often come from decomposing debris.

Keep the lid tightly closed at all times to prevent debris from getting inside. Install a downpipe diverter with a filter to control the flow of water and block larger particles. You can also add mesh over the inlet to catch leaves and insects before they enter. These steps help prevent organic material from getting into the water butt and rotting, keeping the stored water cleaner.

Highlights

Keep the lid tightly closed.
Install a downpipe diverter with a filter.
Add mesh over the inlet to catch leaves and insects.
This prevents organic material from entering and rotting.

3. Keep the Water in Shade

Sunlight encourages algae growth, which causes odor.

Place the water butt in a shaded area to reduce exposure to direct sunlight, which can encourage algae growth. Using a dark-coloured or opaque barrel also helps block light from entering, further preventing algae from forming. It’s best to avoid clear containers, as they allow sunlight in and can quickly lead to unwanted growth inside the water butt.

Place the water butt in shade.
Use a dark-coloured or opaque barrel.
Avoid clear containers.

4. Add a Small Amount of Natural Treatment

These can help control bacteria and reduce unpleasant smells in a water butt, keeping the water fresher for longer. Barley straw is particularly effective for limiting algae growth, while a small splash of white vinegar can help maintain cleanliness. You can also use water butt treatment tablets, which are commonly available at garden centres. However, it’s important not to overdo it, as plants generally thrive best with natural, untreated rainwater.

Highlights

Barley straw (very effective for algae)
A small splash of white vinegar
Water butt treatment tablets (garden centres sell these)
Don’t overdo it—plants prefer natural rainwater.

5. Flush Occasionally

If you’ve not used the water in a while, drain and refill your water butt keep the water fresh and prevent stagnation. Try to use older water on plants before it has a chance to sit for too long, as stagnant water can develop unpleasant smells and bacteria. Keeping the water moving and regularly refreshed helps maintain better quality and reduces the likelihood of odours forming.