I had a Sally Lightfoot Crab for 9 months. I purchased her when my tank was 3 weeks old. At that time, my tank had a lot of green hair algae. The only algae that I have now is the stuff that forms on the sides of my tank. My problem is that this morning she died. I was doing my weekly maintenance which includes a 5% water change with R/O water. I was cleaning algae off the back of the tank glass and moved my filter so that I could clean behind it. Sally was hanging on the filter and moved when I started moving the filter. When I was finished with the maintenance, I found her laying on her back. Everything else in my tank (55 gal.) is happy. I've seen Sally aggressively catch flakes of food and brine shrimp in the past, but I'm wondering why she died. Could it have been from a lack of algae? My salinity was a little high when I started the maintenance, so the water that I used for the change was a little low, nothing drastic. If it wasn't the food, could that have caused her death? My hermit crabs, Yellow Tang, Clown, two Gobies, two Cardinal fish and Coral Beauty Angel fish are doing fine. I just purchased the Coral Beauty yesterday along with several new corals. I feel like my tank won't be the same without Sally, but I don't want to purchase another one if I did something to cause her death. Sally molted twice since I had her. I put 7 - 8 drops of iodine in my tank every morning.