Fiddler Crab and Fish ?

[8taktaktak8]

A friend/acquaintance recently gave me 5 new fish and crab for a tank that I felt was already well established. From what I've read, the Fiddler should not be in my full submersion tank and would best away from the other fish and on his own. The tank has 22 fish, including the new ones.

What's the best way to deal with this situation?

 

[Homer8]

I would say to use this
http://www.amazon.com/dp/B00DH2LV4C...TF8&colid=1XASUQHYFCLHB&coliid=I2BGF3MN1IO5QY

but fiddler crabs live in brackish water. It would be best for it to have its own tank. you could set up a 10 gallon tank with this underwater crabitat and then get some bumblebee gobies.