Creating a proper lid to your fish tank will ensure you are able to feed your fish. It will also keep fish from exiting the aquarium. Covers and lids should be catered specifically to the tanks they will be attached to, allowing for easy access to the inside. A proper lid will also permit viewing fish from above. According to Fish-fl.com, "Aside from keeping your tank lights from getting wet, custom fish tank lids help prevent water evaporation and maintain water temperature."
How to Make a Fish Tank Cover or Lid
Creating a Cover
Decide if you will be using glass or plastic. The cover should be compatible with the tank below. Glass or plastic are good alternatives to wood (which decomposes) or metal (which rusts). Remember to find a material that is durable enough to withstand some general forms of strain.
Measure the top of your aquarium. Record the appropriate dimensions for a lid; these measurements will be dependent upon your specific aquarium. Most tanks allow for the lid to overlap the exposed section below (1/2 inch or more). This prevents the lid from falling into the aquarium.
Use a hand saw (or band saw) to cut your glass or plastic according to step 2 measurements.
Dull the corners and sides with sandpaper; this will prevent accidental lacerations post-production.
Place the rectangular (or square) lid atop the aquarium. Place one or more hinges on the far side—the lid should open towards the aquarium's front to allow for the easiest access.
Secure the hinges to the aquarium by any means necessary: small screws or water-proof rubber cement work best (remember that glass lids can shatter or crack if drilled).