Hi all, I'm brand new here, so new I haven't even had a chance to fill out my profile yet. I did a search on yahoo on "making brackish water" and it brought me here, now I just need the answer. 
I am making a tank for my fiddler crabs who, my research shows, would prefer brackish water. Yet, I can't for the life of me find a "recipe" for making it. I bought a bag of marine salt (Ocean I think was the brand). I bought the smallest bag because (mostly because it was the cheapest) none of them said how to make brackish water only "mix contents with ## gallons of water" and I don't need that much water - not anywhere near it. My tank is sand on the bottom with a "beach" at the end and only a couple of inches of water. So I was thinking if someone could tell me a per gallon ratio. I do not have a hydrometer (is that the right name) nor do I currently have the funds to buy one.
I would appreciate any help. Thanks!

I am making a tank for my fiddler crabs who, my research shows, would prefer brackish water. Yet, I can't for the life of me find a "recipe" for making it. I bought a bag of marine salt (Ocean I think was the brand). I bought the smallest bag because (mostly because it was the cheapest) none of them said how to make brackish water only "mix contents with ## gallons of water" and I don't need that much water - not anywhere near it. My tank is sand on the bottom with a "beach" at the end and only a couple of inches of water. So I was thinking if someone could tell me a per gallon ratio. I do not have a hydrometer (is that the right name) nor do I currently have the funds to buy one.
I would appreciate any help. Thanks!