My crayfish lived for quite a while. The crayfish don't need to get out of the water.. well if its the common Florida variety. Fiddler crabs and some kinds of crayfish need land. Florida blue crayfish are content with a fully aquatic life. They should definitey have a filter. they are messy eaters. SInce the water is actually getting cloudy, I'd say u need a filter. A tiny hang on back filter is great, they love the current. I like aquaclear. They don't need much space although a larger aquarium stays cleaner longer.