What Is the Proper pH Level in a Garden Pond?

Garden Pond Structure

• A garden pond should contain all of the following, particularly if you plan to have fish in it in order to create a pond-like ecosystem: pump, biological filter, submerged and surface plants. A pump circulates the water. A biological filter converts harmful elements in the water, such as waste, to beneficial nutrients. Submerged plants feed on nutrients at the bottom of the pond while surface plants provide shade and protection from the sun. Total plants should not fill more than half of the pond.
  
  

New Ponds

• New ponds will need time to establish their environment. If you plan to add fish, wait at least two weeks. A new pond needs to cycle out chlorine and any other elements introduced through the water you filled it with. The plants added to the pond will be establishing themselves, beginning to establish the pond's ecosystem but they need time as well. It's common for algae to proliferate in new ponds. The lack of plant life gives algae unlimited resources to live on. By adding submerged plants they will compete against the algae for nutrients. Surface plants will shade the water and reduce the sun exposure algae thrive on.
  
  

Making Adjustments

• Adjusting the pH level should be done gradually to avoid shocking plant and animal life in already established ponds. Garden supply stores offer products to adjust the pH and their package instructions should be carefully followed. First try to stabilize the pH naturally through maintenance and adding plants.
  
  

Recommended Maintenance

• Begin testing water pH in the spring and follow up monthly throughout the warmest months. Kits are available from garden centers carrying pond supplies. Also in the spring, clean and repair pump and filter, and clear out debris from the water and strainer. Tend plants that need to be repotted or divided and add new plants to replace what didn't last through the winter. On a weekly basis, remove debris from the water and strainer, and monitor plants. Rotting plant material, fertilizer in new plants or new potted plants, and fish food can raise the acidic level of water. If you add water to make up for evaporation, add water gradually and through the filter so the filter cleans out harmful elements before they can reach the plant and animal life.