Use only the amount your fish will eat completely in about 2 minutes. For a 1/2" fish this is not very much. thaw it in a little water. When thawed strain it out of the water. Do not put the water in your tank, to many nutrients will feed unwanted algae growth. Take thawed shrimp and soak it in a drop of the garlic. using a syringe-turkey baster you can feed the fish and any coral or inverts you may want to spot feed. If just feeding the fish you can just dump it in the tank. Some folks turn off the pumps while feeding, some leave them on. Depends on how active a feeder your fish are. if they like to chase the food leave the pumps on, if they are lazy turn the pumps off. If you turn them off leave them off for a minute or two but don't forget to turn them back on.