David
 Thanks for the advice. My mom's system was installed in the late 1940's to early 50's, and I just want to do everything that I can to make sure that mine lasts at least half that long. She raised 5 children, and basically 8 grandchildren, 4 days a week, on her system, which is only 3 lines, of 25 foot length, and she lives straight across the road from me. We had our rules...only toilet paper (number 2 only lol!) and natural waste down the drains. I follow the same rules in my house. Also, I am interested in doing your treatment on her system (need to replace a disintegrated d-box on hers this summer, discovered during recent maintenance) and my system as well. She has 3 lines, 25 feet each, I have 12 lines, which are 100 feet each.
Rob
Rob
Rob