It has now been 2 weeks since my last treatment and visibility has actually increased to 22 inches, so I decided to let things lay for a while. I am happy with the clarity. I guess it just took time for the Alum to do its full job. I didn't lose 1 fish, so I am very pleased with my results. I want to thank everyone here for the wonderful advice and for taking the time to answer my questions. Yall are great.