Barrel ponds provide an affordable way to add water features throughout the garden, or on a patio or deck. Because they are small, they provide a practical solution for those who want a garden pond but have limited space. Barrel ponds are much easier to maintain than larger in-ground ponds. They do not require expensive filtration systems or pond pumps. However, pond pumps with small fountain attachments can be used for aesthetic purposes and to oxygenate the water.
Place the wooden barrel on level ground in the location you want your new water feature. Once it is full of water, it will be too heavy to move. Place it near an electrical supply if you plan on using a pond pump.
Place the barrel liner inside the pond. If you are using a prefabricated barrel pond liner, simply place it inside the barrel. If you are using a vinyl pond liner that will need trimming, position it inside the barrel, leaving at least 20 cm (8 inches) of overhang around the top. Spread it as smoothly around the bottom as possible. Pleat the liner around the inside walls if necessary. Clamp the liner to the top of the barrel to keep it from sliding while the pond is filling.
Fill the pond with water. While the water is filling, use your hands to smooth out as many wrinkles as possible. Start at the centre of the liner on the bottom of the pond and work out toward the edges and up the sides. As the water level rises, the liner will begin to stretch. You will need to adjust the clamps to loosen the liner and allow it to form to the inside of the barrel. Once the barrel is filled to capacity, remove the clamps and trim the vinyl liner to just below the inside top edge. Hammer upholstery tacks through the top edge of the liner, into the wood to hold the liner in place. One tack every 5 to 7.5 cm, (2 to 3 inches) should keep the liner secure.
Place one or two bricks in the bottom of the pond for a platform for potted water plants. Make sure that at least 7.5 cm (3 inches) of water will cover the top of the pot.
Place a 2.5 to 5 cm (1 to 2 inch) layer of lava rock in the bottom of the barrel around the bricks.
Attach the fountain attachment, which is a rigid plastic tube, to the water outlet on the pond pump. Put the pond pump on top of the lava rock with the tube extending above the water surface. Plug it into an electrical socket and make sure it is working properly.
Add water garden plants that will clean and oxygenate the water. Place potted plants on the bricks. Put floating plants such as water hyacinth directly into the water with the roots submerged.
Add four to five goldfish to the pond after two weeks.
Sunlight will promote rapid algae growth. Placing the pond in a shady area will help keep algae under control. Lava rock provides the barrel pond filter system and provides a surface for beneficial bacteria to live. Beneficial bacteria help to maintain a healthy aquatic environment. They need about two weeks to establish a colony on the lava rock. It is safe to add fish after this time. Change 5 per cent of the water every week to maintain the pond. The water needs to be chlorine free if there are fish in the pond. Tap water contains chlorine which is toxic for fish. Allow it to sit in the sun for two days before adding it to the pond. Pygmy water lilies, water hyacinth, anacharis, milfoil, duckweed and water lettuce are suitable for small ponds. Water plants need fertilisation. Water plant food tablets are available in pond supply shops and some nurseries. Water plants can grow to cover the entire surface of the pond. They will need to be thinned out periodically
Most wooden barrels were previously used to age whiskey or wine, which leaves a residue that can be harmful to fish. To build a barrel pond without a liner, it is necessary to eliminate the residue before introducing aquatic life into the pond. This can be done by filling and replacing the barrel with water until the water stays clear, no oily film forms on the surface and there is no detectable odour. Water hyacinth can also help draw the impurities out of the wood. This process can take several weeks to several months. Smoothing the wrinkles in the pond liner as it fills will make it easier to keep the liner clean, and protect it from rips and tears that could be caused by the lava rock. Koi are not suitable for a barrel pond. They may outgrow the pond and will eat water plants.