[fkshiu]

DI in Vancouver is for those days when TDS goes up a bit like after a bad rain storm or when a crew is mucking about outside. I've always believed that RO/DI (in Vancouver at least) is more for CONSISTENCY rather than QUALITY.

If the TDS is zero after your RO then it simply means your DI will last longer. It won't "go bad" simply by sitting there. It will, however, be ready for those times when the RO doesn't get everything.

On a related note, I remember going into OA many moons ago and speaking to Wendell about all those DI canisters he had coming out of his bathroom plumbing. Where was the RO? He told me that DI was all they used because it lasted so long on Vancouver water. I know he has now added RO, but bulk DI in Vancouver can go a long way.