Disclaimer: Bad photos ahead. Coupled with my poor photography skills and bad lighting, it was difficult to get a good shot of these fish because there were lots of people milling. I didn't want to hold people up who were trying to look in the same tanks I was.
Yes, the ACA is about cichlids. However, cichlids don't live alone in their environment. They share their lake/river/pool with a variety of other fish, including bottom feeders such as Corydora, Synodontis, Ancistrus, and Hypostomus species. Many cichlid keepers maintain tanks containing these types of fish. To that end, there are always bottom feeder species available for sale at the convention, either in the fish room or in guest's rooms.
Above is a photo of juvenile Pineapple plecos (both long and shortfin). The Pineapples are a beautiful orange/yellow in color, and you can see a longfin on the glass near the top.
Below is a photo of juvenile Red Calico plecos (longfin). These are a stunning reddish orange color.
The Cichlid Room Companion
Tropical Fish Hobbyist
American Cichlid Assoc.
African Cichlid Hub