I went to petsmart and had my water tested and ended up having high ammonia levels. I have bought a bacteria supplement and stopped feeding them 3 times a day like the food container said, to feeding them once a day as recommended by the lady at petsmart. However when I added water to the tank (taking 2 gallons out and putting fresh water in and treated it) i notice that food was floating from the bottom, what do I do about this? Do I have to start over? I have three goldfish that are about 3 inches each and one algae eater in a 10 gallon tank.