Whether you're keeping new world or old world cichlids, caves are a good thing. In addition to providing shelter, they're nearly indispensable for cave spawners. Caves can be constructed by simply stacking a few rocks together, or there are even many commercially made ceramic caves available in the hobby. More importantly, what you consider an ideal cave may not be considered ideal by your fish, especially your breeding cichlids that are very specific about the conditions they demand in order to spawn. Needless to say, the options for creating/providing aquarium caves are numerous.
At the ACA convention in July, I had a real nice conversation with Jodi and Brantley Berry, owners of Pleco Caves in Indiana. They make a variety of ceramic and composite-based caves for the hobby, where they specialize in caves for plecos. I was looking for a specific design that I had not been able to find, so I inquired about the Berry's ability to produce a customized, open-ended rectangular tube. A few follow-up e-mails and a few weeks later, they sent me custom samples based on dimensions and other specifications I gave them. They delivered!!
The photos above show the two samples I received. You can see the dimensions in the photos containing the tape measure. One tube is a little shorter than the other, but they're made of the same material, and the inner dimensions are the same for both. I chose rectangles because I want the ability to stack them with some stability, especially on a sand substrate. Also, having external flat surfaces on the tubes provides more stacking options without using silicone or some other adhesive.
The Cichlid Room Companion
Tropical Fish Hobbyist
American Cichlid Assoc.
African Cichlid Hub