Choosing the best aquarium décor for a freshwater angelfish tank should be to the benefit of the fish, not just the observer. The setting should be appropriate to making the fish feel comfortable and at home, and not necessarily one that coordinates with the decorated scheme of the room the aquarium is in. The goal for decorating an aquarium is to provide an environment so the aquarium occupants can lead a normal and healthy life.
Whatever is used in the aquarium shouldn’t change the water chemistry. This includes rocks and shells. Shells are largely calcium, which dissolves and make water hard and shouldn’t be used in a freshwater aquarium. Some rocks and substrates can also change the water chemistry. It is best to get rocks and substrate from an aquarium store as they have been pretested and pretreated to be safe for aquarium use. This caution also applies to fish tank wood. Wood should be soaked with boiling water to remove most of the tannins. Driftwood should be treated to remove harmful salts and minerals or purchased from an aquarium store.
Substrate can range from fine sand to large pebbles for angelfish. Size for pebbled substrate generally ranges between an eighth and a quarter of an inch. Bigger sizes allow uneaten food to become trapped in spaces between the gravel. The type to use depends on the type of fish in the aquarium. Some cichlids rearrange the gravel when they are breeding. To do this the gravel should be about mouth sized. Angelfish however, are not picky when it comes to substrate.
The color should match the biotype or native environment of the angelfish. Some live in dark areas while others in brighter, lighter areas. None naturally live in fluorescent orange environments. A dark colored substrate about 2 to 3 inches deep is acceptable for most angelfish natural habitat aquariums.
Rocks
Some fish live in water with large rocks. The fish use these for protection for hiding. Arrange large rocks in an aquarium to provide caves for the fish to hide in like their natural habitat.
Aquarium rocks shouldn’t have sharp edges that could injure fish, especially the long fins and tails of the angelfish, by causing abrasions. Crevices or see through areas should be big enough to prevent a fish from being stuck in them.
Wood
Wood is used in a blackwater biotope. Bogwood, mopani wood and driftwood are common woods for use in blackwater aquariums. Rocks and plants complete the aquascape. Sphagnum peat moss gives water a tea color suitable for South American cichlids, such as angelfish and discus.
Color
Fish normally don’t experience gaudy colors in the wild. They don’t swim in streams with fluorescent hot pink gravel or plastic plants. Putting these colors in a tank can have the effect of causing unintentional stress to the fish. Fish stores and departments sell these items so it’s easy to think it’s all right to put them in a tank, but it can provide a nightmarish, surreal world for the fish.
Plants
Angelfish, discus and other South American cichlids live in streams with plants. They use these plants to lay eggs, eat and hide. A well-planted aquarium is nice to look at and nice for the fish and an important part of the nitrogen cycle of an aquarium.
However, it takes more effort to care for a live planted aquarium. Plants die and sometimes it is difficult to maintain a well-planted aquarium. Because of that, plastic plants are popular. There is nothing wrong with plastic plants as long as it’s an appropriate color. They don’t die, can be cleaned when they get dirty, and easily rearranged.
Shipwrecks, Castles, and Treasure Chests
Fish stores have an abundance of shipwrecks, mermaids, divers and other ceramic or plastic items for sale. If these items don’t change the water chemistry, aren’t a garish color or have sharp edges, there is nothing wrong with them. Animated objects move by air, so it is similar to an air stone in that respect. However, angelfish, discus or other South American cichlids rarely see a treasure chest in their native streams.