Maintaining optimal water conditions is essential for koi ponds. Factors like pH, ammonia (NH3), nitrite (NO2), and nitrate (NO3) are critical for the health of your fish. Keeping pH levels between 6 and 9 is key for a safe environment, while high levels of ammonia and nitrite can be harmful and may require water changes of up to 50%. Nitrate, although less harmful to fish, can contribute to algae growth. Consider using water test kits to monitor these factors and contact Aqua Ponds for more information.