Yes, your waterfalls add oxygen to your pond water, however, a proper sized aerator creates even more.
All your fish and the good and bad bacteria in your pond consume oxygen 24 hours a day. Any plants and algae in your pond produce oxygen during the day however, plants consume oxygen at night.
A fish’s gills are basically the same as our lungs are to us, they absorb oxygen. The gills give your fish the ability to absorb very low levels of oxygen from your pond water. Your pond water must contain plenty of fresh oxygen for your fish to thrive.
Pond Aeration is vital to strong, healthy, fast growing pond fish and high quality pond water.
Here are just some of the benefits of adding Aeration to your pond
• Increases the oxygen your fish and pond water need to stay healthy
• Removes toxic gases that build up in the bottom of your pond
• Helps reduce pond algae, “algae hates oxygen”
• Enables your “good bacteria” in your pond filter to multiply and thrive
• Increases “low oxygen levels” in your pond that retard growth, increase sickness and can even cause death
• Will greatly improve the performance of any “beneficial bacteria” you add to your pond water
• Stops overnight “fish kills” caused by the oxygen demand of plants and algae at night. Plants and algae produce oxygen during the day and use it up at night, called “Photosynthesis”.
Immediately before daylight check your koi fish to see if they are gulping for air at the surface of the water. You might scare them and they will dive deeper, only to quickly return to the surface. If you have plants or algae in your pond, your koi fish will return to deeper water as the oxygen builds up during the day through photosynthesis.