The ideal pH level for koi ponds is generally between 7.0 and 8.5, which means the water is slightly neutral to mildly alkaline. Maintaining this range helps keep the koi healthy and their immune systems strong. If the pH drops below 7.0, the water becomes too acidic, which can stress the fish and make them more susceptible to illness.
On the other hand, a pH above 8.5 can cause problems with ammonia toxicity and also stress the fish. pH levels can fluctuate due to factors like rainfall, water source, and biological activity in the pond, so regular testing is important. Using a reliable test kit will help you monitor the pH and make adjustments if needed. If the pH is too low, substances like crushed coral or baking soda can raise it safely, while diluted vinegar or commercial pH reducers may be used to lower a high pH.
