While ich will survive that low the fish will be better able to fight it off, thereby giving the presence of making it go away. If you have a hydrometer you can pretty well count on adding .003 to whatever number you come up with on that thing as I've seen them off fairly normally by at least that much.
I used my refractometer to test some fellow reefer's water (because they'd given me frags
) and found that most of them had water up around 1.029! My LFS
sadly SELLS premixed saltwater to 1.017 and says that their reason behind that is that you can use it like that. I don't ever want to buy water from them again, I can tell you. What's the point in buying water if I have to add salt to it anyway. May as well just go ahead and mix the salt myself. *sigh*
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Atlantic City, NJ September 25-27, 2009