There has been a lot of questions lately over on RC about salt mixes. Mainly it was because Reef Crystals had a batch with low Ca and Mg in it. You can read about them on [color=#0000ff>[url="http://www.reefcentral.com/forums/showthread.php?s=&threadid=1270094"]and[/color=#0000ff> [url="http://www.reefcentral.com/forums/showthread.php?s=&threadid=1285879"]here. Just out of curiosity, which salt are you using and why? There has to be a reason for it. I have been using Oceanic for over a year and have had good results with it. A freshly prepared batch has parameters higher than NSW but it works well for me since I keep a lot of SPS. My parameters are steady and the only thing I use is a calcium reactor, no other additives. I tested again last night and my parameters are still within these ranges. Ca 450-500ppm, Alk 8-9dkh and Mg 1300-1400ppm. Plus it's only $.20 per gallon, one of the lowest. Feel free to post your thoughts and results. Below is a chart of salts tested by one of the mods on RC. It's a good comparison between the major brands.