How do I make water brackish?

[Organized Chaos]

I am wondering what I need to do to make my water brackish. I know I need to add salt, but how much? I will be using Doc's Aquarium Salt. I have a 20 gal tank with only 1 Green Spot Puffer. I plan on getting a few more and maybe a bumble bee gobi if I can find one locally. So...How much salt do I need to add? it says on teh box how much to add as a tonic, how much more do I need to add?

Thanks

 

[A.K.A Zak]

i have the same kind of puffer and aquarium salt, i added 4 tablespoons of salt. people say that you should use marine or instant ocean, don't listen to them, i been doing about 36 hours of research straight and found that marine and instant ocean salt has no different effects the aquarium salt, marine and instant salt just have different chemicals in it for a safer saltwater tank and brakish tank, aquarium works just a good and is cheeper, my puffer is doing way way way better then at the store i got him at. he is so active scraping his teeth on my tank to feed him, so so cute. good luck!

 

[Pufferpack]

Brackish water puffers need a great deal more than simply salt, sodium chloride, Na Cl. Depending on the Gh and Kh of your water they may need the buffering and other minerals from marine mix. For a better explanation see:

Article on "Salt"

From an article on Puffers, written by R.T.Ricketts, a highly respected gentleman who has been keeping puffers for 40+ years.

Even if purchased from FW, I start moving these fish to light brackish (specific gravity 1.003 -1.008) gradually over days to a week while they are in quarantine (QT). Aragonite or crushed coral substrates are used to maintain a stable alkaline pH. Only marine mix should be used to prepare the brackish water, and this needs to be done several days before use to allow mixing and solution of all the components. The elevated pH and the complex salts in the mix are important (IME) for these fish, not just sodium chloride (NaCl, plain salt).

I thought I would add the following article on Figure 8 puffers as well just FYI
Figure 8 Puffer Article