Yes I do. I posted them on here a few times before, it is hard to get a good picture showing the caves though. The caves are rarely used now, the tank was built for Malawi cichlids.
Let me look and see if I can find some good pics on my PC.
I have clay pots in my tank. I've had clay bricks, concrete blocks/bricks( these do raise the ph), in tanks. I plan on having a DIY concrete background. All fish hae survived and thrived. Also if you want to be safe and have extra $ you can get a clear epoxy as long as its fish safe to seal the bricks.