Google and found this Italian website, AcquaPortal, which provides many useful data on various marine salts include Tropic Marin, Brightwell - Neomarine, Red Sea Coral Pro..etc . But all in Italian so you need to translate to English by using google translator. I have extracted the Prodac Ocean Reef salt info as below.... From the chart, The mg, ca, KH , pH seem pretty low compare to the Redsea Coral Pro that I am currently using now .