Pentair 72 SqFt Filter Bundle Tie Rod

The Pentair 72 SqFt Filter Bundle Tie Rod (most notably represented by OEM Part #173703 for the FullFloXF® F72 series or #59003300 for high-capacity vertical grid configurations) is a precision-machined structural fastener designed to stabilize the massive internal core assembly of Pentair’s largest 72-square-foot Diatomaceous Earth (D.E.) pool and spa filters. Fabricated from high-tensile, corrosion-resistant stainless steel to survive continuous exposure to pressurized, heavily chlorinated water, this elongated rod acts as the central structural spine of the internal grid nest. It threads straight through the center axis of the core to compressively lock the top distribution manifold to the bottom grid locator plate. When tightened down with a stainless steel wing nut or hex hardware, the tie rod forces all eight individual curved grids into a rigid, perfectly parallel, and equidistant matrix. This absolute alignment ensures that the grid elements cannot twist, flex, or slide out of position during intense pump filtration cycles or high-velocity backwash loops, preventing dangerous structural bypass gaps that could otherwise allow unfiltered debris or D.E. powder to escape back into the pool. Despite its slim 1/4-inch diameter profile, its solid metal construction yields an actual weight of approximately 1.0 to 1.3 pounds (or up to 3.0 pounds when purchased as a multi-rod structural kit), requiring an extended, highly rigid cardboard transit tube with a packaged shipping weight of 2.0 to 4.5 pounds to ensure the precision-cut end threads do not flatten or bend during delivery.