Pond Troubleshooting

What You Observe	Potential Cause	Actions to Take
Fish at the surface breathing air.	Oxygen in water may be dangerously low. Biological filter problems. Parasitic infection	Quickly increase aeration by turning on fountain, waterfall, or add an air pump. Remove fish, place them into non-chlorinated water until pond conditions improve. Use a microscope to examine the gills of a fish.
Fish move slowly, appear sluggish, flashing, not feeding.	A rapid decline in water temperature. Parasitic or bacterial infection.	Remove and carefully inspect fish for abnormalities (visible bleeding, discoloration, scale loss. . .) consult local fish health expert for treatment. Slowly increase water temperature with solar cover or heating device.
Smaller fish are dying, larger fish appear stressed.	Oxygen in the water may be dangerously low. Water chemistry has changed.	Quickly increase aeration. Check water chemistry with test kit.
Water appears light-medium green.	Phytoplankton bloom is occurring due to excessive nutrients, sunlight and warm water.	Add more floating plants to shade water and to reduce excess nutrients. Reduce fertilizer around pond. Add calculated amounts of chemical dye to darken water. Add more submerged plants to absorb nutrients.
Water appears dark green with strands of algae visible.	Algae growth is occurring due to nutrients, sunlight and warm water.	Filter water to remove suspended algae particles. Reduce nitrogen and phosphorus levels. Remove any decaying plant material. Drain/clean pond to remove organic sediments. Install particle filter and/or U/V sterilizer.
Water color is cloudy/muddy but no odor is noticed.	Run-off water has entered the pond. Fish are up-rooting plants or bottom mud.	Filter water to reduce suspended particles. Add gravel to plant container to hold soil. Cover plants with bonnet.
Floating algae has turned brown.	Algae is going through seasonal cycle & has photo-oxidized. pH level decreased.	Harvest decaying plant material. Increase aeration to off-set lower oxygen level caused by brown algae.
Ground fault circuit shuts off.	Malfunctioning ground fault circuit. Electricity leaking from pump.	Consult electrician for electrical inspection.
Submersible pump fails to operate properly.	Pump inflow is restricted. Pump may be damaged.	Remove pump filter attachment or screen device & clean. Install protective pump cage to reduce clogging. Place pump into a pump sock. Replace pump.
Pond level decreases.	Pond leaks. Waterfalls leak. Rapid surface evaporation.	Check plumbing connections. Examine waterfall for leaks. Reduce fountain operation during hot days or strong winds. Inspect pond liner/shell for holes or fractures.