I would not say that 340-360 is the bare minimum. Isn't natural sea water around 360? I had a very successful reef setup with IO and I never even tested for Ca
. Unless you have inhabitants that need a higher Ca
content than most salts will be fine.
There have been many salts tested over the years and I think a new "winner" was always made
Bottom line is that most use IO. Works for some not others. I have used IO, RC, Oceanic and I am now trying Red Sea Pro. I used IO and RC for my FO
and softy systems I have used Oceanic and Red Sea since I need a higher Ca
content and I don't want to dose.
I think pretty much any oft he salts listed above will do the job. Might depend on what you plan to keep.