How to Choose The Best Water Butt
Water butts offer an eco-friendly way to keep your plants hydrated; as opposed to using water from the tap, water butts collect and store rainwater ready for use.
The two main benefits of a water butt are that they keep your water bill down by making use of recycled water, and they benefit plants because the water is free from chemicals like chlorine.
There are a few things to bear in mind when purchasing a water butt, and certain things can be useful to look out for.
Size and Capacity
Water butts come in a range of sizes. Naturally, having a small water butt is better than none, so even a 100 L model can be useful, especially in small gardens. These smaller water butts often have a very small footprint (around 40 x 40 cm), and tuck away easily into courtyards and patios. 100 L is not a large capacity though, and can fill up with just a couple of days of rain. They’re most suited to small gardens and gardens without many plants. You may need to supplement the water from the butt with some from the mains tap if it doesn’t hold enough water for your garden.
If space isn’t too much of an issue, water butts of between 250 – 300 litres are standard size. These will normally be sufficient for most small/medium gardens without overly dominating the space. Much larger water butts are available, going up to a capacity of several thousand litres, but these may be too large for traditional gardens – they can take a long time to fill up, and be hard to tuck away in the garden.
Another important consideration when it comes to size: can a watering can fit underneath the tap?
Some water butts do not come with a base, which can make it difficult to fit a watering can under the tap if the water butt is small. Take note of how high the tap is when buying a water butt. If it doesn’t come with a base you should consider buying one separately as it will help retain the shape of the water butt.
Features to Look Out For
There are a couple of features to look out for when buying a water butt and they may make it more practical to use or assemble:
- A water diverter kit – used to help divert rainwater from the guttering into the water butt, water diverters will be covered in a lot more detail in the following section. Some water butts come with them included, whilst others don’t. It’s also necessary to check that the diverter is the right size to fit on the downpipe.
- An included stand – not all water butts come with a stand, but most of the time you’ll find that one is necessary. Unless the water butt is very large and rigid, a stand should be used to protect the tank and help it stay upright. Another reason why a stand is so important is that it makes it possible to fit a watering can underneath the tap. Without a stand, the tap will generally be too close to the floor.
- Pre-cut holes – these make it a lot easier to set up the water butt. If holes are not pre-cut, you will need to make a hole of around 25-30 mm to connect the water diverter. Given that most people don’t have a drill bit of this size, this can be quite a difficult process. If you want a water butt with pre-cut holes, try to find a model with several pre-cut, plugged holes on different sides of the water butt. This will give flexibility on where the diverter can be connected, and where the water butt can be positioned.
- Hose-compatible tap – some water butts have taps that are compatible with stand hose fittings, such as those for Hozelock and Gardena hoses. Generally, compatibility will be stated. In order to get a more forceful flow of water through a hose, a pump will need to be placed in the water butt.
Using a Water Diverter
A lot of water butts will come with a water diverter included. If not, you will likely want to buy one separately in order to connect the water butt to the guttering in order to collect rainwater.
The water diverter connects to the downpipe of a drainage system. It diverts some of the run-off rainwater away from the main drainage route and into the water butt.
Given that there are both round and square drainpipes, it’s possible to get differently shaped water diverters in order for them to fit on the drain.
Installing a Water Diverter
Putting in a water diverter involves cutting through the downpipe of the guttering. In most cases, these pipes are plastic and the job isn’t too difficult. However, be aware that if you have metal pipes, the job will be more complicated.
The basic procedure for installing a water diverter is as follows (but check any manufacturer instructions for differing information):
- Ensure the water butt is positioned within 50 cm of the downpipe
- If the water butt does not come with pre-cut holes for the diverter, you will have to make these yourself. Measure approx. 10 cm down from the top of the water butt, on the side facing the downpipe, and mark where the hole will go. Use a hole saw with the correct size bit (as per the water butt instructions) to create the hole.
- Using a spirit level, measure directly across from the hole and make a mark on the downpipe. You will need to make two marks, parallel with the top and bottom of the hole you have created.
- Saw the marked section in order to remove it from the downpipe.
- Fit the rubberised splash seal to the top section of pipe, then connect the diverter between the two sections. Make sure that the outlet hole is at the bottom. Then pull the splash seal down over the join.
- Connect the hose: feed the hose through the hole in the water butt and secure it in place with a screw nut. Then attach the other end of the hose to the diverter.
Water Butt FAQs
Can I fit a hose to my water butt?
Some water butts come with taps that are compatible with hose connectors. Check this before purchasing the water butt as it’s not always possible to detach the existing tap. Alternatively, in some cases a hose-compatible connector can be fitted over the tap. The hose will not produce a powerful jet, but it will allow for water to be transported around the garden. To achieve a jet of water you will need to fit a pump inside the water butt.
How can I connect a water butt to the guttering?
Water butts fit to a gutter’s downpipe, so the first step is to choose a suitable downpipe in a location that is convenient. The water butt should be positioned a maximum of 50 cm away from the downpipe.
Place your water butt on its stand. Measure 10 cm down from the top of the water butt and drill a hole large enough for the water diverter. Use a spirit level to measure across from this hole, and mark it on the downpipe. Use a hacksaw to cut the downpipe at this mark. You can then fit the rainwater diverter to the downpipe.
Some water butts come with the tap preinstalled. However, some won’t, meaning that you can choose where to position your tap. If it isn’t pre-installed, you will need to drill a hole and connect the tap through this hole. Make sure you have enough room to fit a watering can under the tap comfortably. Bear in mind that the tap won’t work once the water level goes below it, so don’t place it too high up.
How big a water butt do I need?
The size of water butt you should buy will be dictated by two factors: how much space you have in your garden, and how much watering you need to do. If you only have a small garden or patio, purchasing a slimline 100 L water butt is recommended. It won’t hold a lot of water, but it should be sufficient for most small watering jobs and it won’t take up too much space. If you have a small/medium garden, a standard water butt has a capacity between 250 – 300 litres. This will be sufficient for most of the year. Larger models are available, including water butts with a capacity of 1000 litres +, you just need to have enough space to store them.
The water in my water butt has gone green, what should I do?
When left to sit and stagnate, algae and bacteria can grow on the water in a water butt. Whilst this might not seem like a problem, some of the bacteria can actually be harmful to plants when they are watered – especially baby seedlings. There are chemicals that can be added to the water, but it’s always a risk using chemicals around plants as you never quite know what affect they will have on the delicate chemical balance of the soil. Some gardeners like to use an organic, biologically safe solution of ‘friendly bacteria’ to clear the harmful stuff out.
Of course, this problem doesn’t happen if water isn’t left to stagnate, so some of the best advice is to use the water butt regularly and clean it every year. Keeping a water butt in a cool, shady place will stop it from getting too warm which can also encourage the growth of bacteria.
