Inspection for air duct cleaning. Supplies are in slab, and returns are in attic.Customer had an issue with dirt/sand coming out of front bedroom supply vent. After thorough inspection of attic and air duct system, discovered that several supply boots and possibly the supply Plenum are compromised with fill sand coming in. Explained options of looking into removing fill sand to see if the source is close enough to seal/repair. Also talked about having a senior technician out to give an estimate to flip ductwork up through ceiling. At this point, customer wants to go over options with children and get back with us. Customer did request to go ahead and have returns cleaned today, and understands that the cleaning will only help the system if it is continue to be used in the slab. With a system flip, the returns will likely be replaced. With customer approval, performed a level 2 cleaning on both return ducts. Also advise customer to just use one set of filters, so the customer will just