TAIYO vacation weekend fish food for all tropical fish and never clouds the water. New formula One block will feed 7-12 average sized fish. Taiyo weekend fish food when placed into the aquarium will immediately start to dissolve slowly releasing nutritious freeze-dried foods into the aquarium while at the same time neutralizing aquarium water. One food block will be sufficient for an average of ten gallon aquarium for approximately 3 days. The water temperature should be approximately 76 degree- 78-degree Fahrenheit (24 degree - 25-degree Celsius). as lower temperatures retard the rate of dissolving while higher temperatures will accelerate the release of food particles. Highly alkaline water will also cause a slower release of food particles. Therefore in order to avoid these difficulties a weekly water change of 10% is recommended. Water must be circulated by means of an air stone or filter in order to provide water circulation around the food block.