A healthy fish pond environment requires plenty of oxygen. Fish need oxygen so they can breathe, and water that has oxygen gets filtered biologically. A way to test if there is enough oxygen in your fish pond is to pay attention to signs that might give clues to problems involving lack of oxygen.
Read on to discover how to oxygenate a pond.
Table of Contents
Telltale Signs of Lack of Oxygen in a Pond
- Seeing the fish in the pond gasping near the surface or near other water features is a clear indication that there is a lack of oxygen. Goldfish and Koi, that are real pond fish, need oxygen-rich waters. If oxygen levels get too low, these fish begin to suffer.
- The pond starts giving off bad odors like that of decaying vegetation and other organic matter. This smelly odor indicates that there is a lack of water circulation and filtration.
- If algae start growing to excess and forming a thick layer in the fish pond, there is a lack of nutrients, and you have to clean the pond.
Causes of Low Oxygen Levels
There can be many different factors why your fish pond has low levels of oxygen. One reason might be that there are too many algae, and the temperature of the water is too warm. When water temperatures rise, oxygen levels lower.
Summertime is the time when you have to watch the oxygen levels in the pond the most since plenty of sunshine and an increase of organic nutrients can cause the growth of algae. As a result, during the night with no more sunlight, the algae begin to consume the oxygen in the pond reducing the oxygen levels further.
Appropriate Levels of Oxygen for Fish Ponds
The concentrated levels of oxygen in a pond are naturally low. Usually, a fish pond doesn’t have more than 10ppm (parts per million) dissolved oxygen concentration. When the level of oxygen ranges between 2 to 3ppm is when oxygen concentrations become dangerous to pond life, if this occurs, the fish in the pond can become open to disease and stress.
Fish will start to become stressed when levels of oxygen drop under 3ppm, and concentrations below 2ppm are considered deadly to some fish species. It is advisable to have at least 6mg per liter of dissolved oxygen in ponds.
Testing Levels of Oxygen
It is important to know how to oxygenate a pond and test it for oxygen levels. It is important that you test your fish pond regularly to see if there is plenty of oxygen.
You can purchase test kits that will measure and monitor the parameters of the pond water. The test will indicate if there is enough oxygen and indicate the overall health of your fish pond.
An aeration device can help improve the level of oxygen in your fish pond by increasing water movement and not allowing the water to stagnate. There are pond aeration devices available such as bubblers, spitters, and water fountains that help encourage gas exchange.
There are aeration kits that directly inject air into the pond, so it stays oxygenated all through the year.
3 Pond Aerators for small, Medium and Large Ponds
Tips for Keeping Your Fish Pond Oxygenated
- Make sure there is no decaying matter in the pond, especially settled at the bottom. Remove any debris using a net, skimming the top of the water and a vacuum to clean the bottom of the fish pond thoroughly
- A simple and easy way to add oxygen to a fish pond and provide shade for your pond is to plant floating water plants. Water that has shade will remain at a cooler temperature and will keep it oxygenated better than warm water
- It is a good idea to have a mixture of plants, including floating and submerged ones. These plants will help to decrease the growth of algae. Oxygenating plants like Cabomba and Anacharis help improve the quality of pond water and increase oxygen levels
- Make sure that your fish pond has proper filtration, and that the filter is always clean and working correctly
- Keep the amount of fish in your pond to a minimum because a densely populated pond requires much more oxygen
- During the wintertime, you have to keep a small part of the pond surface from freezing over. You can use an aeration kit or de-icer that will help to maintain an opening, allowing for the exchange of gases and preventing any toxic gas buildup
- Use a de-chlorinator to keep the water in the pond fresh and clean
Oxygenating plants
Pond plants are a great way to add oxygen naturally to a garden pond. However, it only offers a limited increase in oxygen levels and are not always a suitable solution for ponds with bigger fish like Koi Carp.
In small container ponds or ornate garden ponds then plants can really help. Plants like Elodea Densa add oxygen and add a splash of color to any pond. Fast and easy to grow and inexpensive this option is a must for any pond with small to medium fish and no deeper than a few feet.
Read: Best Oxygenating Pond Plants Guide Here!
How to Oxygenate a Pond: 3 Simple Ways to Oxygenate Pond Water
1. Air Pump
You can raise the levels of oxygen in your fish pond by purchasing an air pump. Placing it by the side of the pond, the pump will let the air pump through a small hose to an air stone. This will make bubbles in the water, and when they rise to the surface of the water and break, oxygen is added.
Another thing that the pond air pump is good for is ice prevention in the wintertime. The movement of the air being pumped will help to keep a small part of the pond from freezing over and will let gasses escape.
You have to make sure that you purchase the correct air pump as some are not designed to be kept outside in all kinds of weather. Other pumps have to be put indoors or in a shed and protected from elements. These kinds of air pump models are for larger ponds.
2. Water Fountain
You can choose to add a water fountain to your fish pond. The water breaking at the surface will repeatedly oxygenate the water. It is an inexpensive method that you can use and will also provide an attractive water feature to your pond.
Pond fountains come in many different varieties and sizes, so you have to find one that will suit the kind of pond you have.
3. Water Hose
The simplest way to increase oxygen levels in your pond is by using a simple water hose. Just turn on the water and spray the pond with the hose.
The more extensively and powerfully you spray, the more chlorine gets dispersed from the water. If you prefer to make it easier, you can attach a jet spray to your water hose and place it in your pond.
Obviously this is a temporary measure and can be used in summer when the pond water is at its highest and you need a boost of oxygen quickly.
Conclusion: How to Oxygenate a Pond
The best way to add oxygen to a fish pond is to increase water movement and especially on the surface. Aerators are one of the simplest and quickest way to do this. Plus solar-powered ones are very easy to install.
Water fountains and waterfalls are the ideal way to not only add oxygen to the water but also improve the look and relaxing feel to your pond and garden.
The simple fact that without oxygen your fish and other wildlife cannot survive and therefore is not a matter of if you should add oxygen to a fish pond but a question of how?
I have been working in the tropical fish industry for over 30 years now and I’m still learning. Everyday is a school day in this hobby. In my spare time I play golf very badly!
