I have a dumb question ...

[George]

Originally Posted by reef93

I want to buy Magnesium from Bulk reef, but they have 2 different kinds. One is called Mag Sulfate and another is called Mag Chloride Which one are you guys using in your tank, and what is the difference between them ? What are the benefits from each of them, or do I need to buy both kinds ?

There is no dump question.
You need both to make the 3rd part in Randy's recipe. Randy explains it very well in this article: http://reefkeeping.com/issues/2006-02/rhf/index.php#6
FYI, there is a sponsor here, caco3reef, that sells all chemicals you need for Randy's recipe. After all the saving in shipping and duties and such, caco3reef's price is similar to BRS's price.
If you want to save more, you can buy baking soda and bake it...but yeah...caco3reef has it all.