I wouldn't use IO, simply because it's not as close to NSW
as many of the others (allegedly). The worst thing that would happen would be corals don't grow too fast.
I use many different salts as I mentioned earlier, and also have multiple volleyball sized sps
colonies and sustain these with 10% weekly water changes. No dosing anything. I do have a decent water volume though, so this may not work with an sps
packed nano or 40 breeder (and when I say "sps
packed" I do not mean fifteen 1" frags).
It costs me about a bucket of salt a month. My system is set up in such a way that water changes are pretty easy, and I like doing them for the filtration aspect as well.