Why is pH Important in my Pond?

What is pH?

pH is a measure of how acidic or basic (alkaline) water is. The pH scale ranges from 0 to 14, with 7 being neutral. Lower pond pH represents more acidity and higher numbers represent basicity. pH reflects how soluble different minerals and nutrients are (such as copper, lead, phosphorus, nitrogen, and carbon) and how available they are to creatures that live in the water.

Each number on the scale is 10 times the next number, so water with a pH of 5 is 10 times more acidic than water with a pH of 6. Most aquatic organisms do best in waters with a pH between 6.5 and 8, and the EPA (Environmental Protection Agency) recommends freshwater systems maintain a pH of 6.5 to 9.

Why does pond pH level matter?

A slight change in pH can affect aquatic life in big ways over time. It is much more common for pH to be low than high because naturally occurring substances tend to be more acidic than alkaline. To illustrate, if there’s a lower pH level (5.5-6), some fish may produce extra mucous, have their gills and respiration affected, and have skin issues, making them more susceptible to fungal infections.

All these changes affect reproductive success, which in turn can reduce the population of those fish. With eventual population changes in one species, the entire ecosystem can be altered, all the way down to the decomposition of leaves.

Do I need to test my pond pH?

If your pond is about 2,500 square feet or less, regular (annual) pH testing is a good idea. If you know your pond is prone to be more acidic, you also may want to test it annually. Check with your local university extension office for a pH level test kit and directions.

Agricultural lime is a popular recommendation for how to raise pH in a pond, and it is typically recommended to use during winter so that it can take effect over the following days or weeks. The amount of lime needed will depend on the pH and size of your specific pond. Larger bodies of water usually balance themselves out, but if you suspect the pH of your water is not between 6.5 and 8 or 9, look into a test kit.

Conclusion

So why is pH important in your pond? Proper pH of pond water keeps the ecosystem balanced. For the water body to be healthy, a pH level water test can be performed to ensure your pond is balanced. If you have a pH level too high, the water is too basic, and some minerals or nutrients may not be as soluble. On the other hand, when it comes to how to raise pond pH, using agricultural lime in the winter is recommended.