Originally Posted by ruaround
fresh water only...check your salinity as the water evaporates, the salinity increase the more water you loose...but you also loose some salt to the edge of your tank, filters, and whatever else it can "creep" on.
thats a good point. check your salinity with a refractometer if you can possibly dig up the money to get one. They are pretty cheap online. I got mine for 43, but you can find them on the world famous auction site