Things You'll Need
Instructions
Open the battery compartment using a screwdriver or by sliding the battery door open.
Insert the required batteries into their terminals and replace the battery door securely.
Place the fish in water. Some battery operated fish will work as soon as they contact water. If your fish does not swim automatically check for an "On/Off" switch and move to the "On" position.
Replace the batteries when the fish fails to swim or lags.