EasyPro pH Down provides a safe, effective way to lower pH in your pond. Many factors in a pond affect the water’s pH such as fish food and decaying plant material. When determining whether or not to decrease (or increase) pH, always track the water’s pH over several days by measuring the pH at several times during the day (8 am, 1 pm and 6 pm for example). This will help demonstrate the natural fluctuations in your pond’s pH.  A pond’s pH can naturally fluctuate widely during a 24 hour period. Attempting to make changes to a pond’s daily pH changes may be harmful to aquatic life. Keep records of all pH readings and the times of day the readings were taken. Be sure to use reliable pH test kits.