System 3 Mod Cartridge Filter 300 Sq. Ft. - S7M120


Model # S7M120

By Sta-Rite

  4.5 Average  



Model # S7M120

Warranty 1 Year Warranty on Parts

Alternate Part #'s PENS7M120

Product Description

Inyo Recommended Filters

Pressure Gauge 

Valve And Gauge Assembly 

Tank Body O-Ring 

Drain Plug 

Replacement Cartridge Kit 


With Sta-Rite`s System 3 Modular Media Pool Filters unique design, you can look forward to season-free maintenance every year.

  • Holds 50 Times More Dirt Than A Sand Filter
  • Less Cleaning Needed - Gathers and holds more dirt so you clean less often.
  • Opens Easily - The split tank design allows for convenient access for cleaning or changing filter media.
  • Designed For Safety - The use of Posi-Lok Clamps enables safe, easy access to filter.
  • Durable, Lightweight And Corrosion Resistant - Dura-Glas Exterior
  • Landscape Friendly - Sleek, black tank profile blends well into any landscape design
  • Available In Four Sizes - 300, 400, 450 and 500 sq. ft. filter areas.

For More Sta-Rite Filters

Product Specifications

Port Size:
2 in.
Filtration Area:
300 sq. ft.
Flow Rating:
50 - 80 GPM

?     Asked on 8/14/2021by Peter V Lesar

Is the S7M120 a DE filtering system or a sand filtering system or neither?

A  Answered on 1/26/2022 by InyoPools Product Specialist Joe S.

Cartridge filters take advantage of pleated cartridges by maximizing the square footage of the filter. The larger the surface area, the more dirt particles you can filter out. Cartridge filters can capture debris as small as 10-15 microns. In terms of efficiency, cartridge filters fall the middle. However, they are the easiest to maintain.

?     Asked on 2/19/2018by terry

My system 3 ( s7m120) is 17 years young. I just spring cleaned my cartridges (annually) and when putting the top on and using the 6=7 knuckle fasteners, the unit is leaking at some of the knuckle connectors. can you buy the knuckle connectors if they are not providing a tight grip? It wasn't leaking before I started to take it apart to clean the cartridges... HELP

A  Answered on 2/19/2018 by InyoPools Product Specialist Hector F.

After reviewing the parts diagram for your filter, there is no part referred to as "knuckle connectors" but if you click here you will be directed to the parts diagram for your filter and can see the various fittings and seals that may resolve your leak. 

?     Asked on 10/28/2017by Don

I have a hair line crack in the upper body. Can I just buy that piece?

A  Answered on 10/30/2017 by InyoPools Product Specialist Lennox H.

Hi, Don. Yes, you can replace just the Upper Half Tank Kit - 24851-9000.

?     Asked on 5/28/2017by Terry

Is the S7M120 filtration system sufficient for 32,000 gallon inground pool?

A  Answered on 5/29/2017 by InyoPools Product Specialist Lennox H.

Hi, Terry. The S7M120 is adequate to filter 32,000 gallons of water in an 8 hour period. The max flow rate of this unit is 80 GPM.

?     Asked on 4/28/2017by tom

placed order yesterday...not sure filters are correct. I need replacement filters for S7M120...100 and 200 sf please check my order and see if correct...order # 738509

A  Answered on 4/28/2017 by InyoPools Product Specialist Lennox H.

Hi, Tom. The correct cartridges were ordered for the S7M120 model.

?     Asked on 4/3/2017by Carolyn V Singer

I would like to know if there are any dealers in Pasadena, Maryland that can show me how to hook up the filter for me? I just moved into this house and don't know anything about the filter.

A  Answered on 4/5/2017 by InyoPools Product Specialist Scott W.

We do not have any dealers but we do have a DIY Resource tab on our website that has many videos on working on pool filters.

?     Asked on 4/3/2017by Inyo Visitor

Is the System 3 Modular Media Filter DE or Sand filter? How much do you use? How much are the filters for it?

A  Answered on 4/5/2017 by InyoPools Product Specialist Lennox H.

Hi. This System 3 S7M120 filter is a 300 sq. ft. cartridge filter. They are also System 3 Sand filter's which model #'s are S7S50 and S8S70.

?     Asked on 12/6/2016by RUDY


A  Answered on 12/6/2016 by InyoPools Product Specialist Lennox H.

Hi, Rudy. Yes, with a max flow rate of 80 gpm this filter can filter 38,400 gallons of water in an 8 hour time frame.

?     Asked on 12/2/2016by RUDY


A  Answered on 12/2/2016 by InyoPools Product Specialist Adam Y.

Good evening Rudy, If you are refering to jandy valves than no

?     Asked on 8/21/2016by LOUIS

We installed a S7M120 Sta-Rite Filter---3 Years Ago--- We Now Have installed A Heater-- This year--- Its odd that Every time the GaGe on the Filter ----once it reaches----the No 40----My Heater tells me NO--FLOW--IT STOPS WRKNG-- I CLEAN THE CARTRIDGES----& IT WORKS (HEATER IS A JANDY PRO SERIES JXI) SOMETHING IS WRONG HERE OR AM I DOING SOMETHING WRONG

A  Answered on 9/1/2016 by InyoPools Product Specialist Lennox H.

Hi Louis, As the filter get dirty the water flow through the filter decreases providing inadequate water flow to activate the heater water pressure switch. If you're having to clean out the filter more often then it sounds like the filter module has reached the end of it;s life and will need to be replaced.

?     Asked on 5/25/2016by Juley

Hello, our pool is 9 years old and we are replacing the cartridges in our filter. Does this filter require any sand at the bottom or is it only the cartridges that do the cleaning? Thanks!

A  Answered on 5/25/2016 by InyoPools Product Specialist Alan M.

Hello Juley, This cartridge filter cleaning system does not require any sand to aid in the effectiveness of the filtration. The cartridges will be sufficient enough to filter the pool water on their own. Thanks for the question!!

?     Asked on 5/16/2016by Jason

can I replace the lower filter body? Mine has a crack. The filters are fairly new.

A  Answered on 5/17/2016 by InyoPools Product Specialist Matt S.

The S7M120 lower filter body replacement is part number: 24850-0102S

?     Asked on 5/3/2016by Inyo Visitor

does this filter system come with a top; not shown in picture.

A  Answered on 5/3/2016 by InyoPools Product Specialist Alan M.

This is a complete filtration unit.

?     Asked on 2/25/2016by Inyo Visitor

My pool surface area will be 380 sq ft. Do I need the 400 or is the 300 the pool company wants to install sufficient?

A  Answered on 2/26/2016 by InyoPools Product Specialist Lennox H.

Hi, This unit can filter up to 48,000 gallon in an 8 hour time frame and can handle a flow rate of up to 80 gpm. Which is sufficient for you pool, if you want to can go with the S7M400.

?     Asked on 9/8/2015by Patti

Do you provide names of local installers that we could call. We live in zip code 02152

A  Answered on 9/9/2015 by InyoPools Product Specialist Joe S.

We are simply a on-line retailer in Orlando, Florida and don't have contact with outside installers. It is possible if you were to call Pentair ( who own Sta-Rite ) they may have suggestions for your area. Their number is 800-831-7133.

?     Asked on 7/21/2015by Manny

Is this good for a 30,000 - 35,000 gallon pool?

A  Answered on 7/21/2015 by InyoPools Product Specialist Hector F.

Yes this filter has sufficient surface area for that sized pool. You just need to confirm that the gallons per minute rating with your model pump for your pool is compatible with that model filter.

?     Asked on 5/29/2015by

I made a mistake on my original question, I actually need the information for the right part number for a STA-RITE Modular Media Filter - Model # S7M120. That would be for all filters to include, large and small cartridge and the air bleed filter. Also nee to know if you sell the o-ring clamps for the clamp assembly?

A  Answered on 5/29/2015 by InyoPools Product Specialist Patrick P.

No worries Victor, Here are the parts you will require for the S7M120 and we have all of these items in stock ready to ship: S7M120 Large Outer CartridgeS7M120 Small Inner CartridgeS7M120 Air Bleed Assembly, S7M120 Clamp and the S7M120 Clamp O-ring. You may also view the Complete Parts Breakdown for The S7M120 Cartridge Filter here.

?     Asked on 5/27/2015by Richard

Is your free shipping offer available to addresses in Canada?

A  Answered on 5/28/2015 by InyoPools Product Specialist Bob D.

Hi Richard. Unfortunately our free shipping does not apply to orders in Canada. We will ship UPS or USPS. Thank you.

?     Asked on 4/25/2015by Helga Freitag

What material is inside the starite system 3 model S7M120? Is it corrosion resistant also for salt water?

A  Answered on 4/27/2015 by InyoPools Product Specialist Patrick P.

Hi Helga, The internal and external tank for the Sta Rite System 3 S7M120 filter are constructed of glass-reinforced composite resin. This is a corrosion resistant tank ideal for salt water pools but not for ocean water as ocean water has a salt concentration which is 10 - 20 x's more than a standard salt pool.

?     Asked on 9/21/2006by Guest

Does this come with the filter cartridge and gauges?

A  Answered on 9/21/2006 by InyoPools Product Specialist Patrick P.

This filter comes direct from the manufacturer and includes the cartridge and gauges.


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