It is not a dumb question. There is really no correct measurement. It depends on the
SG you wish to achieve. It will just take trial and error on your part. I use Coralife salt and keep my
SG at 1.024. I know it takes 3 cups of salt for every 5
gal. of water to get my
SG to 1.024 at 80 degrees F.
SG will change slightily with temp. so take your best guess and let the water age for 24hrs and recheck. Adjust by adding more salt or
FW as needed.