Anything comparable to Reverse Osmosis?

I'm getting a new grow put together and I was wondering if there is any type of water treatment that is comparable to RO, but wastes less. The water at this place has a high PH and dissolved solids. Not too sure about the EC. Moral qualms keep me from being able to use RO. Waste not want not and all that.

RO is the shiat, i suggest getting a hydro-logic unit, as they purposely waste way less water than other cheaper ro units.