Search  for anything...

Watts Premier OFPSP OneFlow Plus Whole House Water Filter System & Water Softener, Water Filter Replacement Scale Reduction Cartridge, 1 Pack

  • Based on 0 reviews
Condition: New
Checking for the best price...
$260.35 Why this price?
Save $19.60 was $279.95

Buy Now, Pay Later


As low as $43.39 / mo
  • – 6-month term
  • – No impact on credit to apply
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Apple Pay, and PayTomorrow. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

FREE 30-day refund/replacement

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.


Availability: In Stock.
Fulfilled by Amazon

Arrives Wednesday, Apr 29
Order within 52 minutes
Available payment plans shown during checkout

Protection Plan Protect Your Purchase
Checking for protection plans...

Size: Water Filter Replacement Scale Reduction Cartridge


Style: Water Filter


Features

  • TAC CARTRIDGE: Rated for up to 250,000 gallons, the Watts Premier TAC (Template Assisted Crystallization) Cartridge is designed to reduce scale formation, providing chemical-free scale reduction and protection and improving efficiency of water used in appliances.
  • HIGH-CAPACITY FILTRATION: This OneFlow Plus replacement cartridge converts hard minerals into soft particles, thereby preventing build-up inside pipes and retaining beneficial minerals like calcium, potassium, and magnesium.
  • EFFICIENT FILTRATION: This cartridge does not add or remove anything from the water and operates without chemicals or salt, promoting sustainable, environmentally friendly water treatment technology and leaving only high-quality drinking water.
  • FOR ONEFLOW PLUS: This cartridge is specifically designed for use with the Watts Premier OneFlow Plus Whole House system. We recommended replacing every 250,000 gallons or 3 years, whichever is earlier. When replacing ensure to turn off the inlet and outlet valves on the systems supply and outlet lines.
  • THE PREMIER DIFFERENCE: Since our founding in 1989, Premier has been dedicated to the design, development, and marketing of high-quality water filtration systems that exceed industry standards. Following our Watts Water Technologies in 2001, our audience and influence have only expanded, solidifying Watts Premier as a trusted leader in the industry.

Description

The Watts Premier TAC (Template Assisted Crystallization) Cartridge is a highly efficient solution for reducing scale formation, ensuring your appliances operate smoothly and extending their lifespan. Rated for up to an impressive 250,000 gallons, this cartridge provides long-lasting performance and reliable scale protection without the use of chemicals. Designed to convert hard minerals into harmless soft particles, the TAC cartridge effectively prevents scale build-up inside pipes and appliances while retaining essential minerals such as calcium, potassium, and magnesium. One of the standout features of the Watts Premier TAC Cartridge is its environmentally friendly design. Unlike traditional water softeners that use salt and chemicals, this cartridge operates without adding or removing anything from the water. Specifically crafted for use with the Watts Premier OneFlow Plus Whole House system, this replacement cartridge is an integral component of your home water filtration setup. By maintaining the natural composition of the water and preventing scale formation, the TAC cartridge helps improve the efficiency of water used in various household appliances, leading to fewer maintenance issues and longer-lasting appliances. In addition, installation and maintenance are straightforward with the Watts Premier TAC Cartridge. We recommend replacing the cartridge every 250,000 gallons or every three years, whichever comes first, to ensure optimal performance. When it's time for replacement, simply turn off the inlet and outlet valves on the system's supply and outlet lines to safely swap out the old cartridge for a new one.

Material: Carbon Fiber


Product Dimensions: 3.5"D x 3.5"W x 14.37"H


Item Weight: 1.49 Pounds


External Testing Certification: ANSI


Product Benefits: OneFlow+ prevents hard water scale buildup in pipes and appliances and removes harmful contaminants for better tasting water. See more


Model Number: OFPSP


Product Benefits: OneFlow+ prevents hard water scale buildup in pipes and appliances and removes harmful contaminants for better tasting water.


Brand Name: Watts Premier


Set Name: OneFlow Plus


UPC: 098268085105


Global Trade Identification Number: 05


Manufacturer Warranty Description: The OneFlow (R) tank system is warranted to be free of defects in materials and workmanship for 5 years from the date of original shipment. The OneFlow (R) media is warranted for performance for a period of 2 years from the date of the original installation when installed and operated in accordance with instructions. The OneFlow (R) cartridge system is warranted to be free of defects in materials and worksmanship for 1 year from the date of original shipment. OneFlow Cartridges (R) are warranted for performance for a period of one year from the date of original installation.


Unit Count: 1.0 Count


Number of Items: 1


Manufacturer Part Number: 7100640


Item Type Name: Whole House Water Filter System & Water Softener


Manufacturer: Watts


Included Components: Scale Prevention Cartridge


Material Type: Carbon Fiber


Compatible Water Purifier Models: Watts OneFlowPlus


Item Dimensions D x W x H: 3.5"D x 3.5"W x 14.37"H


Item Weight: 1.49 Pounds


External Testing Certification: ANSI


EU Spare Part Availability Duration: 3 Years


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Wednesday, Apr 29

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Top Amazon Reviews


  • Wonderful having full house filtered
Size: Carbon Block Water Filter Replacement Style: Water Filter
Love being able to take a drink from any faucet and enjoy clean smelling and tasting water. Water pressure dropped significantly after 14 month. Swapped to find the old Olten cakes with sediment from the municipal water system in Washington DC. Will just make a pint of swapping it every 9 months. Yes, it’s a lot more expensive than using a drinking water filter for drinking water only. But we find the value to be well worth it. There’s clearly a benefit to our fixtures and plumbing. We’re confident that all of the water in the house has been well filtered. And we generally just drink more water when we can go to any tap in the house and fill up a cup rather than going down to the kitchen and pouring from a Britta filter. ... show more
Reviewed in the United States on January 14, 2023 by Miles

  • Easy to Install
Size: Carbon Block Water Filter Replacement Style: Water Filter
A friend of mine installed this for me. We had to refer to a video but it was very easy once we viewed it. I knew it was getting near the time to change the filter because my water was tasting icky. Within minutes my water was great again. This filter appears expensive but considering it is for a year, it’s definitely worth the money. ... show more
Reviewed in the United States on December 23, 2024 by Belinda L. Fowler

  • Good product
Size: Carbon Block Water Filter Replacement Style: Water Filter
What a difference this product made with both the taste of our water and with water deposits on plumbing. Works excellent and super easy to change out the filter. Lasted a full year.
Reviewed in the United States on December 16, 2021 by Lisa G

  • Expensive to maintain, hard to find replacement parts.
Size: Carbon Block Water Filter Replacement Style: Water Filter
Very good product. It's built like a tank and does an excellent job. The reason for the low review score - it has a proprietary design and only one supplier (Watts), resulting in a very high total cost of ownership (For example, carbon filters cost $190+ per year! Carbon filters should cost $20-$30 max). This also results in very few retailers holding replacement parts in stock, which means that every year, trying to find replacement parts is an adventure. ... show more
Reviewed in the United States on November 30, 2025 by Yaron Rosenbaum

  • Direct fit, effective
Size: Water Filter Replacement Carbon Block + S... Style: Water Filter
This was a direct fit for my system. The filter set is effective but a little pricey.
Reviewed in the United States on June 26, 2024 by Alicia Sierrawolfe

  • Quallity
Size: Carbon Block Water Filter Replacement Style: Water Filter
Great product
Reviewed in the United States on July 27, 2025 by Tim S.

  • I bought the “opened package” option and it was fine. Saved me $60!
Size: Water Filter Replacement Carbon Block + S... Style: Water Filter
Best filter on the market. Easy to replace cartridges. Scary what’s in our water. When I replaced mine the year old filter was orange!
Reviewed in the United States on September 28, 2021 by Victoria Camilleri

  • Works great!
Size: Carbon Block Water Filter Replacement Style: Water Filter
Works great for our household water from taste to slowing down calcium deposit on faucets and water heater.
Reviewed in the United States on September 10, 2021 by Nancy T.

Can't find a product?

Find it on Amazon first, then paste the link below.
Checking for best price...