I had a sand sifting Starfish for almost a year. I performed a water change on my 20g soft coral tank and ever since I have not seen my Starfish. I've done multiple water changes of large quantities before and it has never effected anything in the tank. Before it would come out at night frequently and patrol the sand bed even during the day sometimes. After a few days of not seeing it come out I started to question where'd it could be or what was wrong but decided not to worry since it would sometimes be days before I saw the starfish as I travel and timing was also a factor. After two weeks I was starting to get worried. Today marks about a month and I sifted through every inch of sand and found no sign of my starfish. The only thing seemingly off about my tank were small hard bindings of sand that looked like small chunks of sand concrete. I've never seen these before in my tank. All my sand it's quite fine in grain with small pebbles and shells here and there nothing like the larger solid chunks of sand I found. Some of them have a grayish stripes and coloring on one side like my starfish had on it's top. I cannot provide any water quality reports aside from salinity and temperature as I do not have those instruments. What could've happened to my starfish?


