Q. My local fish store has some “gold aureum” cichlid fish. I asked the clerk about them, and he said they were Central American fish and needed hard, alkaline water to thrive. In my area, the local tap water is relatively soft and slightly acidic. If I choose to get some of the “gold aureum,” would I have to set up another freshwater fish aquarium (apart from my South American cichlids), or could they be acclimated to my already established fish aquarium? If I had to keep the cichlid fish separate, what would I have to do with the tap water to make it acceptable for the “gold aureum” cichlid fish?
Highland Park, Maine
A. First, the cichlid fish that has been available in the hobby lately and being sold as the “gold aureum” is actually the Thorichthys helleri cichlid. Thorichthys helleri is one of the “firemouth types,” sharing a general color pattern of vertical bars, an opercular (gill cover) spot and a liberal amount of spangling. What makes the T. helleri cichlid fish stand out is its gold-yellow body color. As you’ve seen, it is a very attractive cichlid fish.
To answer your second question first, the fish store clerk was right in saying this cichlid fish comes from Central America (specifically Guatemala and Mexico) and would prefer hard, alkaline water. However, most of the Thorichthys, including T. helleri, are somewhat adaptable in captivity, with respect to hardness and pH. While you probably don’t have to go to great lengths replicating conditions found in this cichlid fish’s natural habitat, elevated levels of hardness and pH more than what are already present in your unmodified tap water may be required. Depending on your tap water parameters, you may be able to provide suitable conditions by adding a liberal amount of crushed coral substrate to the aquarium filtration system, which, over time, will serve to maintain elevated levels of carbonate hardness and pH. I suggest you maintain a carbonate hardness of at least 5 degrees KdH (about 100mg/l of CaCO3) and a minimum pH of about 7.3. Unless your tap water is extremely low in hardness and pH, you shouldn’t have to install a complete aquarium substrate of crushed coral in your aquarium. However, I should warn you that one of the critical water parameters in maintaining any of the Thorichthys species is temperature. These cichlids do not do well in warm temperatures, unlike many South American cichlid fish. For long-term health, provide the Thorichthys with water no warmer than 75 degrees Fahrenheit.
By this point I’ve probably already answered your first question. While it can be done, given the right mix of species, I suggest you don’t house the Thorichthys cichlid fish and your South American cichlid fish in the same aquarium. Generally, most South American cichlid fish prefer softer, more acidic conditions than the majority of Central American species. Add in the lower temperature requirement of the Thorichthys and you have a good case for a second aquarium. Best of luck with the “gold aureum” cichlid fish if you decide to get them!