Is there any downside to buying cheap marble or ceramic tiles at a hardware store and cutting them Into
your own frag disks/tiles? Seems like it's cheap and easy.
I have found the smooth ceramics and marbles are great for sps. With zoa/paly they don't seem to work as well as aragocrete. The polyps seem to try and "run" on the smooth surface. Its almost like they spread to the edge of the disk with lots of space between polyps. The rough surface of aragocrete seems to make them grow closer together.