You need a hydrometer. They're cheap.
I roughly calculated 12 to 15 teaspoons of marine salt for every 4.6 gallons of water. I have a 4.6 gallon bucket to do water changes, and I use a teaspoon to mix in the salt (ergo my bizarre measurements). I use a hydrometer to make sure the salinity is in the right range before putting it in the tank, then I measure the salinity in the tank once I'm done to make sure.
(Read: DON'T just use my rough guide to go by alone!)
I'd say it's best to understock a brack tank. Marine salt is pricey, so there's no sense wasting it by doing so many water changes to try to cram too many fish into your tank.
I roughly calculated 12 to 15 teaspoons of marine salt for every 4.6 gallons of water. I have a 4.6 gallon bucket to do water changes, and I use a teaspoon to mix in the salt (ergo my bizarre measurements). I use a hydrometer to make sure the salinity is in the right range before putting it in the tank, then I measure the salinity in the tank once I'm done to make sure.
(Read: DON'T just use my rough guide to go by alone!)
I'd say it's best to understock a brack tank. Marine salt is pricey, so there's no sense wasting it by doing so many water changes to try to cram too many fish into your tank.
