Can I add this to my tank, or no??

Question

I know you can add salt to a freshwater aquarium to help with nitrite levels (professional from Tetra-care told me that). And I know that table salt is bad for fish. But the only other kind of salt we have is Margarita salt. Can I add that, or is it the same? Because I know that you're supposed to use rock salt. But is it the same thing?

Answer 1

The problem with table salt is that it's iodized and may have other additives not meant for fish which can be bad for them.  A lot of rock salt is contaminated with other heavy minerals that also are not meant for fish, so even though rock salt is not iodized, it's not a good idea to use it in a fish tank.  The best kind of salt to use is evaporated sea salt, which you can buy at the grocery store quite cheaply, or aquarium salt, which is usually pretty much the same thing.