Finally, there are a number of mechanical aids to help us keep our ponds clean and therefore clear:

Nets
Removing floating debris is fairly straightforward -an ordinary pond net will often do the trick, though it needs time and patience if you are chasing small bits of debris around the pond surface.

Pond vacuums
For most of us, the thought of 'cleaning out the pond' fills us with horror because it's a slippery and smelly job. Removing debris and sludge from the bottom of the pond can be fairly difficult, though we are fortunate these days to have aquatic vacuum cleaners to help us out. Remember, however, that a pond vacuum will not turn a cloudy pond into a crystal clear lagoon. It removes the silt, sludge, detritus and potentially toxic substances from the bottom of the pond. Hence algal growth is largely reduced, the water becomes clearer over a period of time, and filter systems are made more efficient. A side benefit is that garden beds and borders will be treated to a fine watery manure which they'll lap up (specially on hungry or chalky soils).

Using a pond vacuum will remove silt and sludge from the bottom of the pond
Most pond vacuum sets comprise a collecting tank with motor unit and 10m (over 30ft) of cable, a 5m (16ft) suction hose, a 2.5m (8ft) discharge hose, a hose-end connector, extension tubes and adjustable suction nozzles. Some more sophisticated types even include a radio remote control with battery and holder.

Operating these pond vacuums is not difficult. The unit should always be at least 2m (6ft) away from the pond edge. Place the end of the discharge hose where the muddy water is to be released when the collecting tank is emptied. This effluent can be directed over any bed, ideally between plants to hide any discoloration of the soil. Connect the unit to the power supply via an RCD and switch it on.

Guide the nozzle to the bottom of the pond, and move it slowly and evenly to vacuum up the mud. When the collecting tank has been filled to its maximum level, a float valve automatically switches off the vacuuming operation, indicated by a high-pitched motor noise. At this point, take the nozzle out of the water and tilt the hose up to allow the remaining water to drain into the tank. Then switch off the unit.

Pond scissors
These are supplied with handles around 115cm (45in) long and are very helpful for cutting through dead weeds; they are particularly effective for the dreaded blanketweed, which can smother plants and choke fish.