Thanks to everyone for voting and/or adding their personal comments. I think I may switch from IO to Oceanic given its similar price and better Ca+ and Alk levels.
One last thing, all things considered equal is Tropic Marin considered the best, but not used as much because it is about 70% more expensive? Why is it so much more expensive? Is it really that much better? Things that make you go hmmh? :?
So is everything else they sell, much more expensibve then the rest of the pack. Actually, Red Sea used to be as expensive as well. but I never liked their salt.
People are sucker for expensive things.........Comparing the last Mercedes I had, I am quite happy with the Camry I am driving now.