Stagnant water in ponds is unhealthy for our fish, as it does not contain enough oxygen. As we all know, fish need oxygenated water in order to live.
In order to solve this problem, the water needs to be aerated. Water aeration means that the water needs to be agitated, and exposed to oxygen. The best way to get this done is to use a pond air pump. Pond air pumps cause movement in the water, and the bubbles expose the water to oxygen, allowing oxygen to mix with it.
Using a pond air pump together with a filter can also effectively remove sulfur compounds (which cause the water to smell bad) and liquid fish waste.
There are many types of pond air pumps available: some are external, and some are submersible. To add beauty to your pond, you can choose to add a waterfall pump.
