We have beautiful new Cambridge pavers around our pool, and we're about to get a new Loop-Loc mesh cover professionally installed by a licensed dealer. Some intense Googling tells me that 15" pipe should be used for installing the anchors into the pavers and ground below. However, both the dealer and Loop-Loc now tell me that 9" pipe is acceptable. That's a big difference. Does anyone know if 9" pipe is really OK for paver installs?