<a href=showthread.php?s=&postid=10078902#post10078902 target=_blank>Originally posted</a> by cayars
You're doing a fresh water test on a salt water tank!
Carbonate Hardness (gH) is meaningless for marine tanks.
In the same kit you will see a dKH test kit. This is what you want to use for a marine tank.
There is nothing wrong with the API dKH test kit. It's by far the easiest kit to use for Alk. Each drop is 1 dKH (it doesn't get easier then this).
Carlo