I would like to feed my ice maker with water from my reverse osmosis unit. I'll be using 3/8" poly tubing (since you can't use copper per the manufacturer). My question is...is poly tubing suitable for use in walls and in the attic? My refrigerator is on the other side of my kitchen from my sink (which has the r/o system under it). It would be extremely difficult to run the line in the lower cabinets.

Any help would be greatly appreciated.