Cichlids are a diverse group of fishes. Primarily differentiated by region, there are hundreds of cichlid species available for hobbyists to keep and culture. Before you decide to bring some cichlids home, it is vital to do your research into their water quality parameters, space requirements, environmental design, stocking densities, breeding practices, feeding behavior and diet. There is no "one rule" for all cichlid species!
Water Quality Parameters
Since cichlids come from so many varied regions, there are many restrictions for mixing species based on water quality alone. Depending on your species and their region, you may require soft, acidic water or more basic, hard water. Many cichlid owners start with RO or reverse osmosis water, since it gives them the ability to manipulate their source water more, especially for acidic, soft water tanks.
Cichlids come in a wide variety of sizes, but don't think that smaller fish need less room! Some species of cichlids can be very aggressive over resources such as territory, hiding places, breeding space, mates and food. Many cichlid owners should consider a larger tank than necessary when mixing multiple species. For species with strict stocking densities, do your research first. If it is your first time with cichlids, stick to easy-going, less aggressive species.
When designing your tank, it's easy to consider what you find appealing, not your fish. Try to consider your intended species entire life cycle. What type of environment most closely resembles their natural environment? If you intended to breed your fish, what reproductive strategy do your fish use? If you plan to use "natural elements," such as found rocks or wood pieces, make sure the species of wood is safe for fish and properly cleaned prior to adding to your tank.
Many owners make the mistake of over-decorating their tanks. Larger fish, fish that stick in schools, flighty or aggressive fish are easily snagged on decor items such as branches or twigs. If your fish need cover, but don't do well with solid objects, consider switching for fake or live plants.
Some aggressive fish may take personal offense to some elements in their tanks and attack them. This could be an odd-smelling plant, a humming aerator or an electronic heater. Necessary elements, such as heaters, may require the addition of a sump to keep your fish from hurting themselves while destroying equipment. If you do not have the option of adding a sump, you may need to fortify your equipment with a false back or secret cave your fish cannot access.
There are a few species of cichlids with very strict stocking densities. Too many fish and they fight. Too few fish and they fight. Trying to balance your population may seem like a losing battle at times. Many cichlid resources leave out this critical information when you are getting ready to purchase fish. It is best to contact your local cichlid breeder or your local cichlid club to make sure your species are stocked at the correct density. Since there are so many different species of cichlids out there, an expert in your species may not be local.
There are many different breeding strategies employed by the various cichlid species. Some are mouth brooders, some will build elaborate caves, others are open water spawners, throwing their eggs and sperm about the tank. If you plan on breeding your fish, be sure you have a male and female and their ideal breeding setup. If you are NOT planning on breeding your fish, try to keep single-sex tanks or be prepared for potentially aggressive, unfulfilled spawning desires. Just because you didn't consider breeding more fish, doesn't mean your fish won't.
Depending on where they live in the wild, various species of cichlids will have different feeding strategies. Some eat at the surface, some in the middle of the water column, and some on the bottom, digging through substrate. Although many captive-bred cichlid species have learned how to swim up at feeding time, you will need to consider how your fish find their food. If you have a lot of surface feeders and only a few bottom feeders, how will the fish on the bottom get enough to eat? Do you have any species who are especially aggressive towards food and will bully anyone who looks at them while they try to eat? Do you have appropriate substrate for bottom feeding fish to dig through? There are many important points to consider when feeding your fish and simply "dumping some food at the top" will not work for every system and species.
Along with the wide variety of cichlid species comes a diverse collection of herbivores, omnivores, carnivores and all levels in between. Depending on what mix of species you choose, you may need more than one diet to keep all your fish healthy. Do not assume on can of "cichlid flakes" will do the job. Many cichlid species do best with a varied diet.
There is no "one size fits all" when it comes to a cichlid tank. Do thorough research before you buy anything! Although you may have your heart set on one species, you may not have the space or setup to house them. Don't cut corners thinking your new cichlids will make do with whatever you have ready. Many of these species have strict water quality, space, diet and other requirements that will cause serious disease and possibly death if you ignore them.