By Nature2



Part # CRG25

Alternate Part #'s W28125, W28125EACH, ZODW28125

Product Description

The Nature2 Proffesional G provides up to 6 months of water purification for your swimming pool. Keep your swimming pool clean. Nature2 G comes in three different sizes. Make sure you select the correct size for your vessel and swimming pool.

Cartridge selection: (three sizes available)

  • 2501025 (CRG25) - 10,000 - 25,000 gals
  • 2501035 (CRG35) - 25,000 - 30,000 gals
  • 2501045 (CRG45) - 35,000 - 45,000 gals
    Cartridge dimensions: 13.75"x4.63"

Click here for more Nature2

Product Specifications

Treatment Capacity:
25,000 gal.
Cartridge Only

?     Asked on 4/6/2020by GARY GREGORY


A  Answered on 4/6/2020 by InyoPools Product Specialist Patrick P.

Yes they are the same size and are interchangeable. The CG35 Cartridge just has more sanitizing agent within the cartridge

?     Asked on 7/2/2016by Inyo Visitor

I have a cartridge model #CG25 - is this filter compatible?

A  Answered on 7/4/2016 by InyoPools Product Specialist Alex V.

Hello, Yes, they are the same.

?     Asked on 4/11/2016by Terry

Will this cartridge replace my W28125

A  Answered on 4/11/2016 by InyoPools Product Specialist Andy O.

Terry- The CRG25 Nature2 G Series Replacement Cartridge 25K (W26725) is interchangeable with the W28125.

?     Asked on 6/25/2015by Huey

Will this cartridge replace my N2CG25?

A  Answered on 6/27/2015 by InyoPools Product Specialist Lennox H.

Hi Huey, The Nature2 G Series Replacement Cartridge 25K (W26725) will replace your N2C525 cartridge.

?     Asked on 4/11/2015by Inyo Visitor

What is the difference between the nature 2 pro g plus 1/g G25 (w26725) n the nature 2 pro g series crg 25 (w26725) besides the price?

A  Answered on 4/13/2015 by InyoPools Product Specialist Patrick P.

These two items would be the exact same so I would go with the one that is less expensive.

?     Asked on 12/10/2012by Guest

I use a product called Baquacil in my swimming pool. Is the nature 2 compatible with it?

A  Answered on 12/10/2012 by InyoPools Product Specialist Patrick P.

Unfortunately Nature 2 is not compatible with Baquacil (or any biguanide system).

?     Asked on 7/14/2006by Guest

I would like to know what type of weekly maintenance (chemicals) is necessary with the Nature2 system?

A  Answered on 7/14/2006 by InyoPools Product Specialist Patrick P.

With the Nature2 you would maintain your pool the same way as if you did not have Nature2.  The only thing that will change is that you will maintain a lower chlorine residual with the Nature2. Instead of maintaining a chlorine residual of 3.0, you would maintain a chlorine residual of 1.5 with Nature2.  This results in using approximately 50% less chlorine.


Est. Repair Time

Less than 1 hr

Tools Needed


Too much chlorine usage

Written on 6/29/2020 by Guest

Balancing pH with soda ash and then hyper chlorinated before installing nature 2 cartridge

Were these instructions helpful? 


Review Summary

 (Average 4.89  out of 5 stars)
17 Rating
5 star:
4 star:
3 star:
2 star:
1 star:

The Most Helpful Review

The Most Recent Reviews