Dynamic Series IV-DFM, DFML, Waterway 35 In-Line Compatible Filter Cartridge letter-size_6 Inch This should be used to

This should be used to the right of a number depth marker displaying total depth and has an overall size of 7 Inch x 6 Inch

Use with Signet Flow Meters and Totalizers

This is a Hayward SPX2600G1 Mounting Foot with Adapter and Screws for Super Pump VS SP2600VSP

This is meaningful because those same products (many of which are phosphate-based) would directly conflict with phosphate removal efforts

Dynamic Series IV-DFM, DFML, Waterway 35 In-Line Compatible Filter Cartridge letter-size_6 Inch This should be used toThe Hurricane HF4335 01 Cartridge Filter is compatible Dynamic Series IV DFM, DFML, Waterway 35 In Line, Guardian 409 219, and 03FIL1300, 17 2482, 25393, 303557, 817 3501, R173431 and other compatible models. It is identical to Pleatco PRB35 IN, Unicel C 4335, and Filbur FC 2385 filter cartridges. The original manufacturer's names and part numbers are for reference only. Hurricane's advanced point bond filter media has tighter filtration capabilities