Minnows must be kept alive and very fresh in order to use them as bait. You can keep a supply of minnows in a tank made from an old freezer. You will need to take precautions to make the freezer safe for children to be around, and you will need to make sure you have the proper system to keep the minnows alive. By following some simple guidelines, you can create your own tank and stop paying bait shop prices by trapping and storing minnows.
Remove the door from a chest-style freezer. You will not have a need to close the door on your minnow tank, and this will make sure children don't accidentally close the door on themselves while playing. Use a screwdriver to remove the hinges. The hinges attach to the outside of the freezer, so the screw holes Will not present the inside of the freezer from being waterproof.
Remove all shelves and compartment dividers. You will need a large open space for the minnows to swim in, so you don't need any dividers in the freezer. If any of the shelves sit on brackets, do not remove the brackets because this could leave holes in the freezer that will allow water to leak. Apply silicone sealant to any screws that are visible on the inside of the freezer.
Fill the freezer with water. Leave the water level four to five inches below the edge of the freezer. You will need this much space because when you net minnows you raise the water level because your hand and the net displace water.
Add an aerator. The water should circulate and have fresh oxygen to keep the minnows alive. Purchase an aerator at a pet shop that sells fish. You will need an aerator that is appropriate for large aquariums, as your freezer/fish tank is probably the size of the largest aquariums pet stores sell.