PH Stabilization for Fish Ponds

The pH is a scale that measures the acidity or alkalinity of a given substance. Low pH means that something is acidic. High pH means it is alkaline. The scale ranges from 1 to 14, with 7 classed as neutral pH. According to the Southern Regional Aquaculture Center, pond pH should be between 6 and 9.

  1. Ammonia

    • Fish excrete large amounts of ammonia into the water. However, ammonia is poisonous to fish and other aquatic life if it builds up. Water pH affects the toxicity of ammonia, according to the University of Kentucky College of Agriculture. The higher the pH, the more toxic ammonia is to fish. Water filters and regular water changes can keep ammonia levels lower.

    Chemical Products

    • Aquarium stores, pet stores and some hardware stores sell chemicals that can lower the pH of pond water. The products are called pond stabilizer, pond buffer and water pH stabilizer. Chemicals that raise the pH of water also are available.

    Household Solutions

    • You can increase or decrease the pH of water b y using common household products. For example, according to the University of Rhode Island, adding baking soda to highly acidic ponds can lower pH. Alternatively, you can raise low water pH with white wine vinegar.

    Plants and Organic Matter

    • Management of pond plants and organic material can help control fish pond pH. Too many plants often causes high pH. The removal of algae, and the thinning out of pond plants, can help stabilize overall pH. Some plants actively reduce pH. For example, small amounts of peat moss can help keep pH levels low. The moss absorbs calcium and magnesium, though if it grows too much, it can affect the alkalinity of the water.

    Normal Fluctuations

    • The pH of pond water will naturally fluctuate throughout the day and according to the season. For example, high temperature can increase pH--so levels are likely to be higher in the summer. The pH also can rise when fish are particularly active. It will increase during mating season, or in ponds with lots of fish. A changes of about .5 in pH level during a day is normal.