Clear, pure water is essential for aquatic life and a sign of a healthy natural pond. Algae blooms, cloudy water, and the death of beneficial species are just some of the problems that can arise from water that isn't of high enough quality because of excess nutrients or toxins. The collection of debris, the deposition of silt, and the excess of nutrients are all threats to water quality that routine maintenance may help mitigate.
Clean out any leaves or branches that may have fallen in the pond. Make sure there's enough water, and add more if needed. Make that the filtration system and pump are in good operating order. Determine the water's pH level and make any required adjustments.
According to common wisdom, ponds of any size should thoroughly be cleaned once every five years, while larger ponds should be cleaned once every ten years.
A pond's deep water also helps keep the water cold even in the hottest summer months. It's preferable for a pond's depth to average somewhere between 10 and 12 feet. Eight feet is the optimal average depth of the water.