Lots of decent salt mixes out there. Given the long history of people having success with Instant Ocean, it's hard to argue that someone switch from using Instant Ocean or Reef Crystals. To boot, they're usually the most inexpensive and have the most well balanced numbers for the average Jo (or Jolene) who's using water changes as the main/only chemistry maintenance activity, while still working well for people with jam-packed SPS reefs like me.
I don't doubt the results people are getting from the other brands mentioned - most salts are at least OK these days - but the test numbers of most other brands make me wonder about their formulation strategy. For example, why do customers of Tropic Marin Pro Reef need higher calcium but lowered alkalinity compared to their standard salt?
The table quoted in
this post (thanks again to Billy Beauchamp for doing the initial testing...has to be one of the most widely used pages in the reefing hobby...at least by me) will show clearly the big differences between the major brands of salt.
For reference if you don't want to click over, I summarized the data into ratios relating calcium and magnesium to alkalinity. Instant Ocean, Reef Crystals, Red Sea Coral Pro and Oceanic are in bold and pulled to the top as they were all mentioned in this thread. The other sets represent manufacturers ranging from Aquatic Gardens to Tunze.
Ca:Alk:Mg
37:1:117 Natural Sea W
ater
36:1:123 Instant Ocean
38:1:111 Reef Crystals
70:1:186 Coral Pro
68:1:194 Oceanic
55:1:155
34:1:104
62:1:153
38:1:117
38:1:117
45:1:138
49:1:109
64:1:193
51:1:132
50:1:163
39:1:109
50:1:140
54:1:145
38:1:123
53:1:162
44:1:142
(Remember these are ratios just meant to compare with the other ratios...the numbers themselves are not too useful for anything else.)
My interpretation is that something in the range of 38:1:120 seems to be a good ratio (close to natural sea water). Salt mixes with relatively low alkalinity content (like Oceanic and Coral Pro) will appear to have "inflated numbers" for Ca and Mg in this table. I'm not sure who wants lowered alkalinity (the most crucial of all three elements - and what most tanks are most deficient in) but there's a range of salt makers targeting you.
Interestingly, Crystal Sea's (once Forty Fathoms) Marinemix is the only one to really nail natural sea water ratios, with Instant Ocean and Tropic Marin (regular) being next closest. Crystal Sea also is by far the most inexpensive salt mix I've seen at retail. $40 per 150 gallon box even at a relatively expensive local fish store. Being mostly a lab product it's not widely carried at local or online retail outlets, however.
-Matt
