
Pentair Bottom Bulkhead for Quad DE and FNS Plus Filters, 178575Z
30 day returns · Easy, with prepaid labels provided
Quick overview
- Genuine Pentair Factory part 178575Z, not an aftermarket fitting.
- Quad D.E. filters Pentair lists it as the bottom bulkhead for the Quad D.E. filter.
- FNS Plus The product title also lists it for FNS Plus filters, so it covers both families.
- Base of the tank The bulkhead is the fitting at the bottom of the filter, where the tank meets its plumbing.
- Stops a base leak Weeping at the bottom of a DE filter often traces back to the bulkhead rather than the tank itself.
- Serviceable part Replaced on its own, without buying a whole tank bottom assembly.
Need a hand?
Frequently bought together

Bottom Bulkhead for Quad DE and FNS Plus Filters, 178575Z
Similar products
Other products people compare with this one.
Pentair Clamp Bolt for Purex and Nautilus Plus Stainless DE Filters, 070428Z$1799
Pentair 9.5 inch Internal Air Bleed Assembly for FNS Plus DE Filter, 190092$3499
Pentair FNS Plus Stand Pipe O-Ring, 59000600$1899
Pentair Genuine OEM FNS Tank O-Ring, 195008$4599
Pentair Genuine OEM Strainer Air Vent, 172855$2999
Pentair Triton Air Bleeder with O-Ring, 273512Z$1799
Pentair Nut Machined, 194989Z$1799
Pentair Genuine OEM Machined Nut, 194997Z$1999
Pentair Manual Air Relief Assembly, 98209803$3299
Pentair 154747 Genuine OEM Spacer Washer$2199
Pentair Tank Clamp Knob, 76033$1899
Pentair 2" FNS24 All Purpose Plug with O-Ring, 195830$2199
Pentair Tie Rod, 1/4 in x 21-1/2 in, 36 Sq Ft DE Filter, 59001500$4899
Pentair Manifold Top with Air Bleed for FNS Plus D.E. Filter/RPM Titan & Nautilus Filters, 59023700$14899
Pentair Template for FNS Plus Filter, 98725800$1399
Pentair Genuine OEM Inlet Pipe Assembly for FNS Plus, 190043$11199
Pentair Tank Lid for FNS Plus FNSP60 DE Filter, 170022$41199
Pentair Genuine OEM Tank Bottom Assembly, FNS Plus 48 Sq Ft, 170017$47399
Pentair FNS Plus Tank Bottom Assembly with Stand Pipe | 170018$59999
Pentair Genuine OEM 36 SQFT FNS Plus Tank Lid, 170020$30199
Product details
The Pentair 178575Z is the bottom bulkhead for the Quad D.E. filter. The product title also lists it for FNS Plus filters, so it turns up under both families; check the model plate on your tank before ordering.
What it does
The bulkhead is the fitting at the base of the filter tank where the tank passes through to its plumbing. It carries the full pressure of the system and is sealed against the tank, which makes it one of the first places to look when a DE filter starts weeping low down.
Replacing it
The bulkhead is a serviceable part in its own right, so a base leak does not automatically mean a new tank. If the tank body itself is cracked or distorted, the complete tank bottom assembly is the larger repair, but a failed bulkhead is fixed with this part alone.
| Brand | Pentair |
|---|---|
| Manufacturer part number | 178575Z |
| UPC | 788379671525 |
| Type | Bottom bulkhead |
| Fits | Pentair Quad D.E. filters |
| Also listed for | FNS Plus filters |
| Position | Bottom of the filter tank |
| Shipping weight | 0.3 lb |
| Ships | Parcel |
Request a quote
Need a volume price, a freight quote, or pricing in writing before you order? We reply the same business day.
From Pentair
Pentair equipment
Pentair SuperFlo VS 1.5 HP Variable Speed Pool Pump, EC-342001
Pentair MasterTemp 400 Natural Gas Pool Heater, EC-462028
Pentair Clean & Clear Plus 420 sq ft Cartridge Pool Filter, EC-160301
Pentair IntelliConnect Control & Monitoring System with Wi-Fi, EC-523317
Genuine Pentair parts
Pentair Genuine OEM Seal Kit for WhisperFlo and IntelliFlo Pool Pumps, 356198
Pentair Genuine OEM High Flow Manual Air Relief Valve, 98209800
Pentair Genuine OEM FNS Plus Element Assembly Complete, 48 Sq Ft, 59023400
Pentair Genuine OEM MasterTemp/Max-E-Therm 6-Button Control Board Kit, 461105Z



Customer reviews
More from Pentair
Pentair SuperFlo VS 1.5 HP Variable Speed Pool Pump, EC-342001$1,48900
Pentair SuperFlo 1 HP Single Speed Pool Pump, 115/230V, EC-348190$74800
Pentair WhisperFlo VS 2.6 THP Variable Speed Pool Pump, 115/208-230V, EC-011533$1,79900
Pentair Genuine OEM HiFlow Valve 1.5 in. 6-Way Clamp Style, 262506$20999
Pentair 110/220V IntelliChlor Salt Chlorine Generator Power Center, EC-520556$79900
Web Price
Pentair IntelliChlor Plus and LT Replacement Sensor Board, 523769$40499
Pentair 3.2 kW IntelliFloXF VSF, VSF, VS+SVRS, i1, i2 Motor, 350305S$78199
Pentair IntelliChlor Plus40 Salt Chlorine Generator Replacement Cell, 40,000 Gallons, 523735-EC$1,81900
Web Price
Pentair Rainbow 320 In-Line Chlorinator, R171096$14999
Pentair Genuine OEM Clamp Kit with Tension Control, 190003$31099
Pentair IntelliChlor LT25 Salt Chlorine Generator Cell, 25,000 Gallons, 523747-EC$1,15699
Pentair IntelliFlo VS+SVRS Variable Speed Pool Pump, EC-011057$2,39900
Sta-Rite 170145 System 3 S7M120 Large and Small Cartridge Set, 25021-0200S and 25022-0201S$47999
Pentair 2 in. Multiport Valve Kit for Side Mount Sand Filters, SM-20-3, 261055$30899
Pentair IntelliChlor Plus Controller Replacement (HMI), Black, 523770$39599
Pentair 2" Valve Kit Multiport, Side Mount DE Filters SM20-2, 261152$30799
Pentair WhisperFlo and IntelliFlo Volute Housing Replacement Kit, 357149$29699
Pentair MicroBrite Color LED Pool Light 12 Volt, 14 Watt with 100' Cord, EC-620425$61900
Pentair Genuine OEM FNS Plus Element Assembly Complete, 48 Sq Ft, 59023400$40599
Pentair Amerlite Pool Light for Inground Pools with Stainless Steel Facering, 500W 120V 50' Cord, EC-602128$43900
Web Price
Questions and answers
What people ask about this product, answered by our pool techs.
Which filters does this fit?
Where does the bulkhead sit?
My filter is weeping at the bottom. Is this the part?
Do I need to buy the whole tank bottom?
Get your unadvertised price ›






