Instant ocean reef crystals

[stellarfly]

I recently visited the local lfs to look at salts. I was thinking about starting my tank with instant ocean reef salt since it's popular, and a lot of people use it (including mr. Saltwater tank). One of the reps told me not to use it with ro/di water! I was like "what?!!" he stated that instant ocean reef crystals does not mix well with ro/di water. I thought to myself "this is rubbish!"

Any thoughts. He recommended red sea salt. I was under the impression that instant ocean reef crystals is a decent salt. Any thoughts? I don't want to pay $100 for salt per bucket. I mean come on!

Let me know