Water Quality

Pond water quality is among the most important things to consider and monitor. In this section, explore various resources on pond management and water quality. Learn more about pond fisheries management and the role of aquatic plants in the pond ecology. Tips on winterkill, common water quality concerns, and harmful algae blooms can be accessed as well.

Pond Water Quality and Testing

Water quality plays an essential role in ensuring a healthy pond. Water quality problems can range from muddy water to nuisance growth of aquatic plants and fish kills. Many of these, however, can be prevented with proper management techniques. Practices to incorporate include water testing and monitoring, maintaining a riparian buffer, and reducing nutrient sources to the pond.

To assess pond water quality and prevent potential problems, carrying out water tests on a regular basis is necessary. In general, there are two main options – purchasing a readily available test kit or submitting a sample to a certified water testing laboratory. The state-accredited testing lab at Penn State, for instance, offers a specialized Pond Water Quality Testing program. The program tests for common parameters and provides recommendations along with the test report.

Different variables contribute to different water quality issues. Depending on the pond’s main use, water quality parameters to monitor may include pH, alkalinity, phosphorus, hardness, and iron. Additional measures of water quality for ponds used for recreational purposes are E. coli bacteria, nitrate-nitrogen, aluminum, and sulfate.

In this section, you can access Penn State Extension’s resources on pond water quality, such as the Five Steps to a Healthier Pond webinar to identify problems early and manage nutrients, plants, and wildlife. Information is also available on managing pond winterkill.

Ponds and Algae Bloom: Pond Scum

Aquatic plants and algae play an integral role in the pond ecosystem. Water plants – as well as planktonic algae – are beneficial for habitat, wildlife, and nutrient absorption. Excessive vegetation, however, is often an indicator of poor health and water quality.

Various aquatic plants can cause water quality problems in a pond. More commonly these include duckweed, watermeal, and filamentous algae. Duckweed and watermeal are common pond scum types. While both plants are important food sources for numerous organisms, they can quickly reproduce and cover the entire pond surface under the right conditions.

Filamentous algae is a dark green plant that, over time, forms floating mats and gas bubbles. During summer months and under certain conditions, algae can produce toxins, also known as harmful algal blooms (HABs). These toxins can kill animals and wildlife, produce skin irritation, and cause noxious odors. Among the most common species of harmful algae in Pennsylvania are Aphanizomenon, Microcystis, and Anabaena.

Managing Pond Water Quality and Aquatic Plant Growth

Penn State Extension provides a number of valuable resources on pond water quality and aquatic vegetation. On this page, discover information on nutrient control for preventing aquatic plant and algae growth. In addition, access a free webinar discussing study findings on harmful algae blooms in inland ponds and find advice on protecting animals from HABs.

Valuable information for pond owners is also featured in the Aquatic Plants and Algae section. Topics covered include types of water plants and invasive aquatic species, as well as controlling excessive growth and applying herbicides.