Oxygen is an important part of keeping pond water healthy, it occurs naturally in the water but may quickly dissipate, especially in hot weather when fish can be seen gasping for air on the surface.
1. Add a Pond Air Pump
A very simple way to add oxygen to the pond is to add an air pump. Sitting at the side of the pond, it will pump air through a small hose to an air stone and bubbles will enter the water. When the bubbles break the water's surface oxygen will then be added.
Another feature of a pond air pump is that it will also act as an ice prevention tool in the winter, the movement will prevent a pond freezing over completely, leaving a small hole free for gases to escape.
Make sure you buy the correct the pump, some are designed to sit outside in all weathers and others need to be indoors or in a shed for protection from the elements. Larger models pump a greater amount of air, more air stones and air lines can be added, and these models naturally suit larger pond systems.
2. Turn on Your Fountain or Add One
You can also introduce a fountain, this will mean water is breaking the surface constantly which is when oxygen will be added. This is a very inexpensive method with the added bonus that your pond will benefit from an attractive water feature.
Pond fountain pumps come in a wide variety of sizes so buy one that's right for the size of your pond. You don't want a feature that's going to spray water out of the pond, on the other hand, if the feature is too small it might not make an impact. So make sure to look at the width and height that the fountain pump can achieve.
3. Spray Water in With Your Hose
If you don't have either an air pump or fountain, and don't want to purchase them, or there is an emergency, then the best and most simple way to add oxygen back into the pond is by spraying water with a hose.
You don't need to worry about the chlorine in the water either, the more violently you spray the water into the pond the more the chlorine is dispersed from the water, so a good way is to put the water on a jet spray into the pond.