DEAR BARRY: We moved into our home about three months ago, and this week we had a professional inspection of the septic system. The septic contractor found a large mass of tree roots in the tank and recommended that we flush about 10 pounds of copper sulfate down the toilet. He said this would eventually kill the roots. I'm concerned that the copper sulfate won't get rid of the roots, or that it might harm or kill the two large trees in my front yard. What do you recommend? --James more...