While it's easy to neglect the bottom of your cichlid's tank in a rush to create a gorgeous aquarium, the substrate -- the substance on the aquarium bottom -- you choose can strongly affect your fish. The proper aquarium bottom promotes a healthy ecosystem and good fish health.
PH is a measure of your tank's acidity, and most cichlids prefer a pH slightly above 7. The right substrate can also promote healthy plant growth and can encourage natural cichlid behavior. Some cichlids, for example, dig in their substrate. Improper substrate poses a choking and poisoning hazard, because cichlids frequently try to eat material at the bottom of the aquarium. There is no one right substrate for every type of cichlid. Instead, you must consult the specific environmental needs of your cichlid and consider the needs of your individual tank. For example, if the pH is already good, you don't need a substrate that will raise the pH.
Crushed coral and limestone are both substrates that can help raise pH and maintain the pH at a slightly elevated level. Cichlids are unlikely to eat these substrates, and crushed coral is available in a variety of colors. These substrates, however, can be difficult to clean and should be at least 2 to 3 inches thick.
Large river rocks provide an attractive, easy-to-clean substrate that will not alter the pH. Don't take rocks directly out of the river, as these may contain parasites or bacteria that could harm your fish. Instead, buy the substrate at a pet store, and rinse the rocks off before putting them in the tank. River rocks work especially well for cichlid varieties that do not like to dig, and an aquarium vacuum is usually sufficient for cleaning rocks.
Brightly-colored small aquarium gravel is not a good option for cichlids. Dirt and sand may clog your filter or radically alter the pH in unpredictable ways. If you are incorporating new cichlids into an established community, no substrate is a good option in a quarantine tank. It ensures no parasites or bacteria develop that are transferred to the fish. No substrate is also a good temporary option for cichlids with skin conditions and other illnesses.
- African Cichlid Tank Beginner's Guide: Substrates
- Cichlid Forum: Setting Up a Lake Malawi Cichlid Tank
- The Cichlid: An Owner's Guide to a Happy Healthy Fish; Mary Ellen Sweeney
- The Cichlid Aquarium; Paul V. Loiselle
- cichlid image by Earl Robbins from Fotolia.com