Product Overview

Repair a damaged lower housing on a compatible 21-inch Sta-Rite System:3 pool filter without replacing the complete filtration system. This genuine Pentair replacement bottom tank half is designed for targeted housing repairs, while serviceable components may be reused after a qualified technician inspects them.

It fits specified cartridge, D.E., and sand filter models. Check your equipment label and replacement-parts diagram before ordering; a similar-looking tank does not confirm compatibility.

Key Features

Compatible models: For System:3 S7M120 and S7M400 modular media filters, S7D75 D.E. filters, and S7S50 sand filters.

21-inch configuration: This lower housing is not for the larger S8M150, S8M500, S8D110, or S8S70 models.

Lower half only: Includes one replacement bottom tank half, not a complete filter; the upper half, filter elements, seal, clamps, and plumbing accessories are not included.

Repair-focused replacement: Replaces the lower tank shell rather than the upper lid, and does not change the filter’s rated capacity or filtration method.

Product details: Black; product weight is 43.3 lb. Shipping dimensions are 30.5 × 30.5 × 26.25 inches.

Specifications

Warranty & Compatibility

Have a qualified pool service professional inspect the tank sealing surfaces, upper housing, clamps, fittings, and internal parts before deciding what can be reused. Follow the applicable Pentair manual, and never loosen filter clamps while the system is pressurized.

Once the correct model and repair parts are confirmed, this replacement can help keep a serviceable System:3 filter in use.