Benefits of RO water?

Hey guys im lookign into buying a RO filterer. Where im at i have to buy all of my water and it gets expensive. so buying this filter will pay for itself over time. Useing RO water should i get specific RO nutes or additives?
And basically what is the benifts of running your system with RO water. Is it really noticeable?

= Almost 0 ppm. / great help in PH stability .
You will need to get some Cal/Mag + w/use of R.O. or end up w/ defs.
Peace
Crispi :jointsmile:

CONTROL!!!!!

haha Weedhound beat me to it...

complete control.