DIY Aquarium Night Light

During the day, many aquarium owners illuminate their tanks with a light. However, the underwater show doesn't have to stop at night when this light turns off. You can create a soft moonlight effect in your tank by adding a night light to your aquarium. This feature can be made at home in just a few steps. When it's installed, turn it on at night to watch the nocturnal fish and invertebrates come to life.

Things You'll Need

  • Transformer, 12-volt DC at 300mA
  • LED that performs between 470nm and 480nm
  • Wire cutters
  • Wire stripper
  • Resistor
  • Soldering iron
  • Electrical tape
Show More

Instructions

    • 1

      Determine the supply voltage of the transformer. This number should be printed on the device itself. Find out the needed amount of voltage to operate the LED. Also, determine the needed current in miliamps, or mA, to drive the LED. These figures are typically found on the LED packaging under the manufacturer's specifications.

    • 2

      Use the transformer's supply voltage and the LED's running voltage and needed current to calculate the needed size resistor for the night light. The resistor, which will protect the LED from being overdriven, must be the correct size for these features. To calculate the proper size for your night light, visit the Oznium Web site found in the Resources section.

    • 3

      Ensure the transformer is unplugged from an electrical source. Locate the output side of the transformer. This will be the opposite side from where the cord plugs into an electrical outlet. Use wire cutters to snip off the output connection plug just below where it meets the rest of the cord. Inside you will see two internal wires.

    • 4

      Pull apart the two internal wires using your hand, separating them about 6 inches. If you're not able to disconnect the wires by hand, use a wire cutter to pull them apart. Use a wire stripper to remove the plastic sheathing from the top 1/4 inch of the wires.

    • 5

      Locate the positive lead of the LED. This leg comes off the bottom of the LED and will be longer than its negative counterpart. Connect one of the resistor's wires to the LED's positive lead. This can be done by twisting the wires together or with a soldering iron.

    • 6

      Connect the transformer's positive wire to the resistor's remaining wire. Again, this can be done by twisting or with a soldering iron. Attach the transformer's negative wire to the LED's negative lead.

    • 7

      Insulate the connection by covering it with a layer of electrical tape.

    • 8

      Secure the night light above the aquarium. This can be done by taping it inside the tank's canopy. Ensure the device is safely secured from falling in or making contact with the water. Plug it in at night to provide a soft light for your aquarium.