My frogspawn looks like it's loosing flesh at the bottom and has hard red things on it. Dried flesh? Could this be from to much light? I moved it to the top of my rock earlier this week.
The brownish red spirally tubes are vermetid snails. You can superglue the end closed or scrape them off or crush them. They can be an irritant to corals with their mucus net to catch food. Especially when numbers can go off the charts..