Put a FREE ad up on Kijiji with the details and a pic telling them to go to 900 block of Bob Street.  Put the tank at the end of your driveway, or on your lawn.  Put a FREE sign on it.  It will dispose of itself.  
 
I've gotten rid of so many things this way...disgusting old vacuum, window blinds, old mirrors, rickety chair, used clothing/towels.  It's amazing what people will take when it's free.  
