Why a small water feature earns its place

A fountain the size of a dinner plate will not transform your garden's ecology, but it will transform how the space feels. The sound of moving water masks traffic, gives a patio a sense of depth, and draws in birds and insects that would otherwise pass by. On a compact plot, the trick is to think of water as a piece of furniture: something deliberately placed, sized to suit, and looked after properly.

Everything below works on a balcony, a courtyard or a few square metres of paving. None of it needs excavation, and most of it can be lifted, emptied and moved when you want to rearrange the pots.

Choosing your type of feature

• Small fountains. A tabletop or pedestal fountain typically holds 5–20 litres. Look for a pump rated around 200–400 litres per hour, which is plenty to push a gentle plume through a 150–250mm spout. Choose a wide, shallow bowl: narrow deep ones splash constantly and lose water fast.
• Bubble rocks. A submerged pump feeds water up through a drilled stone, so it appears to well up and tumble quietly over the surface. They are the quietest option and the kindest to neighbours, because the sound is a low murmur rather than a splash. A 400–600 lph pump suits a stone roughly 250–350mm across.
• Container ponds. A half-barrel, glazed pot or old ceramic sink, at least 45cm across and 30cm deep, holds around 100–150 litres. That is the smallest volume that will stay reasonably stable through a hot spell and support a few plants and invertebrates without constant intervention.

Siting, power and weight

Put the feature where you will see it from the kitchen window and hear it from a chair, but not where you will be forever topping it up. Full sun in July means evaporation of a centimetre or more a day from an open container. A spot that gets morning sun and afternoon shade is ideal.

Weight catches people out. Water weighs a kilogram per litre, so a 150-litre container pond plus its pot and gravel can exceed 200kg. On a patio this is usually fine, but check for hollow-sounding slabs and consider spreading the load over a paving slab or a sheet of marine ply. On a balcony, keep to the smaller end and check your lease.

For power, use an outdoor socket protected by an RCD, and run armoured cable rather than a trailing lead. Pumps are low voltage and IP68-rated for continuous submersion, but the plug end still needs protecting from rain. If you cannot get power outside, solar pumps with a small panel and battery have improved enormously and will happily run a modest bubbler for six to eight hours on a decent summer day.

Planting a container pond

Keep it simple and native. Aim for roughly half the surface covered at midsummer, which shades the water and slows algae.

• Oxygenators: hornwort or curled pondweed, weighted and dropped in. These do the heavy lifting for water clarity.
• Floating plants: frogbit, which is native and easy to thin out, or a single water lily in a dwarf variety for anything over 60cm wide.
• Marginals: water forget-me-not, brooklime, water mint and marsh marigold, standing in a basket of aquatic compost topped with gravel so it does not cloud the water.

Skip goldfish. A small pond will not support them, and they eat the larvae that make the feature interesting. Let invertebrates arrive by themselves: within weeks you will have water boatmen, diving beetles and the first damselflies.

Making it safe for wildlife

Steep-sided containers are a trap. Wedge a piece of stone or a rough ramp from the water surface to the rim so frogs, hedgehogs and beetles can climb out, and keep the water level no more than 5cm below the edge. Birds need a shallow shelf to bathe on, so rest a flat stone just under the surface.

Top up with rainwater from a butt where you can, refilling gently so you do not wash out the tiny life in the water. Never use tap water treated with a conditioner aimed at fish tanks, and avoid algaecides entirely.

Keeping it going through the year

Check the pump monthly. Lift it out, rinse the impeller housing under a tap, and clear any blanketweed from the intake grille. Blanketweed is best twirled out with a stick rather than treated chemically.

In autumn, net the pond or float a mesh cover over it so falling leaves do not rot down and turn the water black. Before the first hard frost, either lift the pump and store it in a bucket of water indoors, or leave it running just below the surface, where moving water resists freezing. If ice forms, do not break it; melt a hole by resting a hot pan on the surface, and float a tennis ball to keep a gas exchange point open.

With a little winter care, the whole thing costs you perhaps twenty minutes a month and pays back in sound, light and the constant small drama of things arriving to drink.