Horseshoe Crab

This guy was the reason I placed an order here. When he arrived, he seemed very healthy. When released into my tank, he went straight to the bottom and started digging. 2 days later I found him laying on the bottom of the tank upside down, I flipped him over and he was still alive, but I could tell he wasn't doing well. The next morning he was dead. I'm no beginner and I had my water tested by a local salt water supplier that stated my water conditions were perfect. Wish I knew what happened.

I ordered 3 and all are doing great. My kids love watching them. The biggest one we have likes to swim upside down all over the tank and land on top of the rocks. Hes so funny to watch.