I just bought a RO unit from lfs. The guy really suggested I use one when starting up my new tank. My question is, do you really think its neccesary? I use well water from the house and my 55g has been fine for 8+ months? I don't mine using it but the 50g a day unit seems to be producing about 25g a day and this thing is going to take way to long to fill my 150. Can I skip this unit and use straight well water again?