Young Macdonald's Farm Alkalinity Alkalinity is another factor interrelated with others such as pH, CO2 and ammonia nitrification. In a functioning biofilter the bacteria remove carbonates from the water to produce bacterial mass. The energy to do this comes nitrification, comes from therefore, as the amount of ammonia removed by the biofilter increases the amount of alkalinity in the system will decrease, the process also produces acids which further reduce the alkalinity of the system. If the proper alkalinity is not maintained in the system, the pH will drop due to the lack of buffering and bacteria in the filter stop functioning due to lack of carbohydrates. We maintain from 75-120 ppm in the system by adding sodium bicarbonate on a daily basis. Testing will indicate amounts to be added, this is not as complicated as it may seem for under a routine of adding the same amount of feed each day. In fact about 7 grams of alkalinity is consumed by the biofilter to handle 1 gram of ammonia. You can project your alkalinity demand from your feeding regiment. NOTE: SEE - Remote water quality management