Brackish water "recipes"

[oneponygirl]

Hi all, I posted this in beginner questions but haven't received an answer so maybe y'all can help. I have two fiddler crabs that I am setting up in their own tank and it is my understanding that they prefer brackish water. However, the marine salt at my LPS only has instructions for "mix this bag/box with ## gallons of water..." and I don't need that much water. Does anybody know a recipe for brackish water that will tell me how much salt (and if there is a particular brand that is good) per maybe only a gallon?

I would appreciate it, thanks!

 

[nmonks]

Making up brackish water is easy.

Hello,

The quick way is to use a hydrometer, and add salt until you get what you're after. Note that it may take 20 minutes for the salt to fully dissolve, especially in cold water.

The alternative is to estimate (or weigh) a certain amount of salt out and add it to a bucket of water. Normal sea water contains 35 grammes of salt per litre. So, 25% strength sea water, which would be ideal for fiddler crabs, contains about 8-9 grammes (i.e., 35/4) of salt per litre.

I wrote a computer program (free, Mac and Windows) that helps with this. It has simple sliders you pull across for converting between absolute concentration, specific gravity, and relative salinity compared with sea water. You can see a screenshot below. It comes with instructions and tooltips, and I think you'll find it easy to use.

http/homepage.mac.com/nmonks/software/software.html

Cheers,

Neale

 

[oneponygirl]

Wow, that's wicked cool! So are some of the others you have there. I'll have to check them out. Thanks!