I found on Download.com a sort of nice program... It's called Aquapilot...
It lets you keep track of diferent type of tanks including saltwater, freshwater, reef tank, brakish, and even a pond...
It makes charts of the PH, alk, calcium, PO3, NO2, NO3, MG, etc...
It even has alarms that you set so it can remind you to change a filer pad, water change, etc...
The program over all is ok because it lets you keep track of everything you do to your tank...