If I have a spring running into my pond do I still need aeration?
Scott – Ripon, WI
Natural springs are an excellent source of water to fill and maintain a farm pond or lake. The volume of water and the rate at which it flows into your pond varies depending on the magnitude of the spring. While a higher magnitude spring can provide a great deal of water exchange they do not do much to help boost the oxygen level in your pond.
Great deals of pond owners believe their water body is spring-fed because the pond water is cold in the deeper areas of the pond. Pockets of cold water are more often caused by a lack of adequate water circulation which leads to water stratification in the water body. This allows a top layer of water which is heated and oxygenated by the surrounding atmosphere to stay at the top of the pond while the water at the bottom of the pond stays trapped, cold and devoid of oxygen. A couple great indicators that your pond is spring fed are that the water level tends to stay the same regardless of rainfall or lack thereof in your area, or if your pond has an outlet and is constantly flowing. Since spring water tends to be colder you will notice that spring fed ponds are cooler even when properly aerated but the entire water body will be cool, not just random pockets of water.
Properly aerating a water body requires not only circulation but the addition of oxygen that can be absorbed into the water column. For this reason, a spring fed pond is not a direct substitute for a proper aeration system. Aeration systems are designed to not only move water around your pond but to boost the dissolved oxygen content of the water column. Bottom plate systems like the Airmax® Aeration System utilize air compressors and membranes to pump oxygen to the bottom of your pond and then break it down in to small enough bubbles that are absorbed into the water column. This process also forces the water above the plate towards the surface of the pond causing a mushrooming effect that circulates the water body. These type of systems can be used year round. Fountains can also be used to aerate water bodies. Since they draw from the surface of the pond, fountains are usually better suited for ponds 6’ deep and shallower while bottom plates systems work well in deeper ponds. Fountains pump water from the pond and spray it into the air in fine droplets that absorb oxygen and then crash back into the pond. With this principle in mind you might be able to guess that a fountain that sprays a thicker or solid stream of water adds less oxygen to the pond than one that has a finer spray pattern. While effective in shallow water bodies, these systems are best used only for summer aeration.
Almost every pond can benefit from aeration as it not only provides oxygen for fish but also promotes faster muck digestion and an overall cleaner pond. If you have an aeration system in your pond but are unsure if it is properly aerated you can take temperature readings in multiple depths and areas of your pond and record any extreme variations which indicate a lack of circulation from your aeration system.
Pond Talk: Pond owners implement natural springs to create interesting water features in their ponds in the form of artesian wells and water leveling features which you can find online. Have you found a unique way to take advantage of your spring fed pond?