With the recent publishing of our market research report we have found some interesting tidbits. One that caught our eye is the fact that 24% of reef aquarists do not use reverse osmosis water. Let me say that again. 24% of reef aquarists do not use reverse osmosis water. While not a “must” when keeping a fish-only saltwater aquarium it is highly recommend to use RO water when setting up a reef aquarium. You just don’t know what is in your water, and that is why it is suggested to use reverse osmosis water. These 24. Who are these people? Have you met them? Do they act normal?