Do cichlids need small gravel?

I recently converted a 55 gallon community tank into an african cichlid tank. I have two in the tank at the moment, an electric yellow and an electric blue. I kept the same gravel in the tank that I had in the community tank because it was set up for almost a year and had generated plenty of beneficial bacteria. The gravel is about pebble sized rocks, something that cichlids at their current size wouldn't be able to move. I know cichlids enjoy digging pits, and I'm wondering if it will be a big problem if they're not able to. The two in there seem to be displaying perfectly normal behavior so far.