One of the most important aspects of a healthy pond is aeration. Often overlooked, proper aeration can be the difference from a bright green, algae-filled pool to a crystal-clear thriving Fish Pond.  Most ornamental pool fish require clean, cool, well-oxygenated water.  Improperly aerated water will be low in dissolved oxygen, one of the most underused indicators of proper water quality.  It can also stratify the water column, creating different layers of water quality.  Water column stratification is the most common cause of hair algae.   Properly aerating the water will create a healthy environment for your pool fish, and eliminate the most common problems of Koi Ponds.

Determining how much aeration is necessary can require some trial and error.  The accepted method for determining proper water flow through the filtration system is to pump the entire pond through the filter at least once per hour.  This may not be sufficient aeration however.  Depending on the shape, size, and structure of your Fish Pond, the flow from the filtration system may not properly aerate the entire pond.  This is the most common mistake.  If the filter is external, the flow may be returned to the pond using a stream or waterfall.  This may diffuse the current, creating low flow areas on the opposite side of the pond.  Often adding an additional outlet from the main flow can correct this problem.  Many people will add supplemental flow through a dedicated pump or air pump.  This will ensure proper flow through the filtration system, and proper aeration in the pond itself. 

Proper aeration can also prevent mosquito reproduction.  Mosquitoes prefer stagnant pools of water, and an aerated pond will not be preferred.   By keeping the population low, the pond fish will gladly consume any additionally present larvae.  This will ensure a safe outdoor environment for you and your family.

Although they can be a bit pricey, a dissolved oxygen meter is one of the best tools for a Pond Fish Culturist.  The Dissolved Oxygen or D.O. Meter will test oxygen levels in all segments of the pond, and can easily detect inadequate flow.  With a D.O. meter, you can also detect changes from morning to afternoon.  When the water is the warmest, it has a lower capacity to maintain oxygen levels, and be just even stress to induce disease or even death if the levels get low enough. 

In addition to a well rounded maintenance routine, properly oxygenated water will ensure healthy fish in your outdoor Fish Pond.  A well oxygenated pond will be less likely to grow algae, it will be more crystal clear, and will have very little mosquito activity.  In areas that get cold enough for hibernation, proper aeration will keep the ice from covering the entire surface of the pond.  This will keep prevent oxygen deprivation during the winter hibernation, which is the most common cause of death during that time.  Aeration related problems can be the easiest to fix.  By fixing them before they become a problem, a healthy environment can be maintained for years to come.