I had good results with IO but I now use Oceanic. I switched when I started buying more SPS
corals. For softies, I think IO is good. I had really good growth in my softies with PC
lights and IO. For hard corals, a higher Ca
would be preferred.
I am on my second bucket of Oceanic and I get Ca
430 and Alk
of 3.5 meg/L out of the bucket. These numbers work well for me.
Oceanic is a bit more expensive for me though so it is a trade off. Both are good but depends on what you want and how much you want to spend.
I will say that my last bucket I ordered from DrsFoster&smith. No extra shipping charges!