How to Replace a 10-Gallon Aquarium's Light Ballast

Replacing an entire hood because of a faulty light ballast might seem cost-effective for a 10-gallon tank, but being able to replace small items, such as a worn-out ballast, can help to make you a proficient aquarium hobbyist as well as lowering the operating costs of owning an aquarium. With a simple Phillips-head screwdriver and a replacement ballast, fix that broken hood you've been thinking about replacing.

Things You'll Need

  • Phillips-head screwdriver
  • 120V 50/60 HZ electric ballast
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Instructions

    • 1

      Remove the fluorescent light from the 10-gallon hood by rotating the bulb slightly to release the fluorescent bulb pins from the holder. Set the bulb off to the side.

    • 2

      Remove the four Phillips-head screws that holds the white plastic light reflector to the light hood. The screws will be reused, so they should be set off to the side. Removed the reflector from the hood. The ballast is connected to the underside of the reflector.

    • 3

      Remove the light-mounting tabs from the reflector. Each mounting tab is connected to two wires each. Those wires are in turn connected to the ballast. These tabs will not be reused, because the replacement ballast will already have new tabs wired to it.

    • 4

      Remove the two orange wire nuts that connect the ballast and the hood's electrical switch. Disconnect the two wires that were covered with the wire nuts. Make note of which wire is connected to the wire wire on the ballast and the black wire on the ballast. They will need to be rewired in the same manner later. The orange wire nuts will be reused.

    • 5

      Remove the old ballast from the reflector by removing the two Phillips screws that hold the ballast to the reflector. These screws will be reused, so they should be set off to the side.

    • 6

      Mount the ballast onto the underside of the reflector using the screw holes and the screws that the original ballast was attached to. This will ensure the ballast and reflector mount back into the hood correctly.

    • 7

      Place the light-mounting tabs that are wired to the new ballast into the reflector so the fluorescent light can be mounted back into the hood. Attention must be paid to the orientation of the mounting tabs so the tabs are placed into the reflector correctly. The side of the mounting tabs with the metal contacts should face each other to allow the pins in the fluorescent light to connect with the ballast.

    • 8

      Connect the white wire of the ballast to the correct wire on the switch. Connect the black wire to the correct wire on the switch. Twist the wires together using the orange wire nuts that previously removed.

    • 9

      Place the reflector back into the hood and secure the reflector using the four original screws used to mount the reflector.

    • 10

      Reinstall the fluorescent light into the hood and test the light by plugging it in and turning it on.