Test your pond water to determine what you want to correct. Do you need to correct odor, parasites, color or all of the above? Know the variables and condition of your water before you shop for and purchase a water filtering system.
Install a hose suction system into the pond in a clean area with little debris, according to the system's instruction manual.
Attach the hose suction system to a water filter. Some filters are manual, some are electric and need to be plugged in to an electrical outlet. Read the manual for your pump to determine how to operate it. If it's a manual pump, press the handle of the water filter down repeatedly to draw water through the hose and up to the filter system. If it is a more permanent system, support the hose or pipe in the pond using a float.
Place the filter's hose into a gallon container or bucket in preparation for filling it with the filtered pond water.
Continue to pump the handle to deposit clean, drinkable water into the receptacle -- this action draws dirty pond water through the filtering system, which cleans it.