Reply #19: some tanks....

[unkachuck]

....have a baffle at the inlet....this area might get clogged when it rains hard and the solids rise....I broke my concrete inlet baffle out with an iron bar and let it fall to the bottom of the tank....now the solids can rise and fall at the inlet without wedging between the inlet and baffle....

....also, an old 4 inch cast iron drain pipe from the house to the tank may rust/scale up and the hole may shrink to less than 2 inches inside diameter....long hair will snag on this rust/scale and build up over time blocking flow....you may have to rod this pipe out periodically depending on how many people use the system....we keep strainers in the tubs to keep hair from going down and we use short silk stockings on the washer drain to keep the lint out....