Subject: Why have I been unable to grow my own stalactites/stalagmites?

I've been trying to grow my own stalactites/stalagmites for a science project.  
The instructions were to warm water (not boil) and add Epsom salts until they 
will not longer dissolve. Pour into 4 glass drinking glasses.  Tie clean 
washers to the ends of black yarn and criss cross letting hang down slightly in 
the middle.  Nothing happens..we've done it twice and have even run a 
humidifier the second time.  It's very frustrating!

Re: Why have I been unable to grow my own stalactites/stalagmites?