I added 80lbs LS to one of my tanks last night (on top of 180lbs southdown). The LS hardly cloudied the water at all, especially compared to what the SD did when I added it. Southdown is a much finer grain (at least mine is) than LS, so it stirs up easier and stays suspended longer. As was said before, the LS is also saturated, which will help keep the mess to a minimum.