Simple steps for cleaning a fish pond

Fish ponds should be cleaned regularly, because fish urine, like that of other animals, contains toxic ammonia. The best approach is to work with nature rather than against her. Even a small pond is a complex ecological system, and the right mix of two plant groups — submerged plants to oxygenate the water and floating plants to provide shade — will help control algae.

• This consists mostly of removing debris such as dead leaves from the water.
• Use a long-handled swimming pool skimmer net.
• Don't expect your pond to be absolutely clear; the water should be more of a pale green. Environmental balance takes a long time to establish, so don't be too quick to upset it by emptying and refilling the pond.

• This is called for when there is a lot of muck or too many fish in the water. The pond may have been overstocked, or the fish may have multiplied. In either case, you may have to find new homes for some of your scaly friends.
• A rule of thumb is that each fish in a pond should have about a barrel of water.
• The best time — and many experts say the only time — to clean a pond is in very early spring, when cool temperatures provide a less stressful environment for the fish and plants.
• Even so, always keep the fish and plants that you remove from the pond in the shade to avoid stressing them.

• Start by removing the edge plants and then the floating ones, pot and all. Put them in the shade.
• Use a bucket to draw water off the top (the cleanest part) of the pond. Place a children's wading pool in a shady spot and fill it with the water, which will be the right pH and temperature to hold the fish. Save as much of the rest of the pond water as you can in extra containers, unless it is really disgusting.
• Start removing the remaining water with a pump or siphon (a length of garden hose will do). As the water level drops, remove the submerged plants and put them in the wading pool, too.
• When the pond has been half drained, remove the fish with a net and transfer them to the wading pool. Cover it with a mesh screen, in case you have any fish that are likely to jump and flop out.
• While there is still water at the bottom of the pond, clean the sides with a soft-bristled scrubbing brush. Continue to drain until the bottom layer of crud is in sight. Then stop pumping and remove the remaining debris with a dustpan.
• Rinse the sides of the pool with a hose and then remove the pump and rinse that. Gently scrub the bottom.
• Replace the plants before you begin refilling. Use a water conditioner, available from pet stores or aquarium suppliers, to neutralise chlorine in the new water. Return the water you saved in the extra containers to the pond, and allow the clean fish pond to warm up a bit before putting the fish and the water from the wading pool back in.