Unfortunately I have the 'pleasure' of dealing with people like your friend almost every day. Many times I can only barely resist the urge to :rant2: them a new orifice. If your friend absolutely will not listen to any good advice and keeps killing fish, try and 'convince' him to sell you the tank once he gives up in frustration. When he sees it set up and flourishing at your house, it will maybe open the door for you to re-school him on how to keep fish.