I got an electric blue crayfish about 4 weeks ago, and one night he suddenly died. Can you guys help me figure out why? Here is what I did: fed him 1 shrimp pellet every other day and a peice of lettice every saturday, kept him in a 10 gallon tank at 73°F, had 1 hiding spot, a log to climb on, and a fake plant, had a filter, gave him light for 3 hrs each day, no light when he was molting, when molting didnt feed him for 2 days, then took his shell out and fed him normally again, water changes every saturday, left him in the tank for water changes, emptied the tank to half and then refilled for water changes, used about 1/2 tablespoon of water conditioner every water change, had marine sand, and one day after a waterchange he was falling on his back a lot and moving very slowly and clumsily with his tail under him. I came to check on him at about 11:30 p.m. and he was dead. Please help me understand why. Thanks!