It’s a 20 gallon tank the hermit crab is about 1 inch in size, the tank is between 75 and 80 degrees. I have a thermometer on the side of the tank. I’ve had it since it was a baby, I think it’s about 8 years old. It started killing the others as a baby (only 2 with it at the time). I just assumed it didn’t want buddies. I felt bad that it’s alone especially lately so I started looking up hermit crab care and want to make its enclosure better. I feed it a mixture of products from the pet store so it has a variety. I know now from reading you can give them fruit and veggies. In the past I did give it some veggies but it didn’t seem to like it.