Fish are not picky when it comes to aquarium decor. As long as they have a couple of decent hiding places, they'll be happy with their aquarium set-up. Elaborately decorated tanks are for the pleasure of the fish keepers, rather than the fish. The cost of decorating the tank can often come close to--if not surpass--the cost of the tank. A few do-it-yourself items can cut down on the cost of decorating your aquarium.
Lay toy marbles over your aquarium substrate for a more decorative appearance. This is a excellent way to recycle your child's old marble collection. You can also glue marbles to the back of the aquarium, creating a 3-D effect.
Glue together slate rocks with an aquarium-safe adhesive to form caves and tunnels. Fish will appreciate the hiding places they provide. You can purchase slate rock at aquarium supply stores, or search in slate-rich areas near your home.
Build castles, people, or vehicles from small plastic building blocks to place in your aquarium. You can make complete underwater scenes from building blocks. Glue weighted washers to the bottom of the finished pieces to keep the objects from floating.
Lay a terra cotta pot on its side, at the bottom of the tank. Terra cotta pots are remarkably affordable, and available at most craft stores. The pot will provide a hiding place for your fish. Place some substrate in the pot to help it blend with the bottom of the aquarium.
Bake a cut open coconut in the oven at 65.6 degrees Cor one-and-a-half hours. Scrape the meat from the shell with a spoon, then place the shell in boiling water for five minutes to remove of some of the acid from the shell. When you place the clean coconut shell in your fish tank, it will add a Caribbean feeling. The shell can also serve as a spawning place for some breeds of fish.
Use ceramic figures--glazed or unglazed--as cost-effective aquarium decorations.
Some paint can be toxic to fish. If you are uncertain of the type of paint or finish on an object, do not put it in your aquarium.