just bought a red sea mag test kit. I can't seem to gat an accurate reading with it. I know my mag is low, it tested 900. but after adding a lot of mag over the last week it still tests the same. Has anyone had prob using this test kit? Also I have tested some new salt water from red sea and it tested low around 900. Is the salt low and is this causing my tank to test low or is the test crap. Has anyone tested red sea salt? If possible can someone test it for me if they do have it. Thanks for the replies.