OneFlow - Industrial High Flow ANTI SCALE SYSTEMS

£2,640.00 - £2,200.00 (exc. VAT)
£3,360.00 - £2,800.00 (exc. VAT)
  • Chemical-free scale prevention and protection – converts hardness minerals to harmless, inactive microscopic crystals making OneFlow® an effective alternative technology to a water softener for the prevention of scale due to water hardness
  • Virtually maintenance free – No salt bags or other chemicals to constantly add
  • No control valve, no electricity and no wastewater
  • Uses environmentally friendly “green” technology
  • Improves efficiency of all water using appliances – both hot** and cold
  • Simple sizing & installation – all you need to know is pipe size and the peak flow rate
  • Perfect system for towns or communities where water softeners are banned or restricted
  • Manifold assemblies for easy installation of multi-tank, highflown applications (Can be operated in parallel for high flow applications.)
  • OneFlow® does not remove minerals or add sodium to the water supply
  • OneFlow® can be installed as pre-treatment to reverse osmosis (OneFlow® should be the last stage in treatment unless a point-of-use system is being used down stream.)

Replacement Media

OF1465RM Media should be replaced every 3 years

OF1665RM Media should be replaced every 3 years

What is OneFlow®?

OneFlow® is a water softening media that allows for the safe neutralisation of the hardness mineral, Calcium Carbonate. This media can be used to protect central heating systems, boilers and pipework. It may also be used to protect and guard your equipment and machinery from mineral build-up and ultimately, failure.

How does OneFlow® work?

OneFlow® works by detecting the Calcium Carbonate ions within a water supply and neutralising them. This process prevents the minerals from forming lime scale further down the line and building up, causing damage to equipment as well as internal pipework and plumbing. The OneFlow® media can be delivered by either a vessel or cartridge dependent on your application, space available and volume of water required.

The OneFlow® system simply requires an inlet and outlet connection before the system is ready to go. Much like conventional water softeners, OneFlow® requires the water to be particulate free to ensure optimum results. If there are suspended particles with the supply, a 5-micron pre-filter would be required.

How is it different to water softening?

Water softening works by Ion exchange. The ion exchange resin attracts the calcium and magnesium ions from the water, replacing it with a sodium ion. Once the resin has reached the point of exhaustion, the calcium and magnesium is then washed away and the process will start again. Water softening has been used the world over and is a reliable and proven method of softening your water. There are however some downsides to water softening that must be given some serious consideration.

Water softeners discharge a large amount of waste water. This waste water is not only ‘hard’ water, it also contains very high levels of sodium that can prove problematic when large quantities are sent to drain.

Water softeners also use a lot of energy, not only during the softening process but also during the regeneration process. They also require plenty of space for the water softener and the brine tank.

One of the main and arguably most important differences between water softening and OneFlow® is taste. Softened water is not intended for drinking water and would require further filtration to reduce sodium levels to ensure is was safe for regular consumption. The taste as you may expect is slightly salty and the water has a ‘flat’ taste to it. Many find the taste undesirable.

Water softeners require little maintenance. This being said, they do still require regular monitoring including resin checks and bring tank refills. It would be reasonable to suggest that depending on the size of your industrial system, ½ – 1 hours would be required daily to maintain a water softener. With the OneFlow® system, there is no monitoring that is required after the instillation process until the time comes where the media requires replacement. This is because there are no serviceable parts involved. For cartridge systems, replacement is required annually and for tank based systems, this is extended to every three years.

What applications can OneFlow® be used for?

Ideal applications for OneFlow® are virtually limitless. The systems can be applied to large scale commercial or industrial projects as well as smaller scale or domestic projects. Some of the ideal applications include RO pre-treatment, boiler feed, office buildings, housing complexes, heating systems, hotels, restaurants, food production and laundry services to name a few.

What does OneFlow® remove from water?

OneFlow® has no effect on other minerals, particles or contaminants contained within water. It individually targets and neutralises the Calcium Carbonate and leaves everything else unaltered. Municipal water is dosed with various different chemicals and minerals to keep it parasite free and to achieve a desirable taste. Some counties also dose their water supply with fluoride. This sometimes controversial decision is made for the benefit of dental health. When using OneFlow® all of the good minerals will remain within the water. If you require removal of any of these minerals or chemicals, there are alternative systems available to do so.

What does OneFlow® leave behind?

As the question above has stated, noting will actually be removed from the water supply, the calcium carbonate will simply be neutralised. If the water was potable going in, it will still be potable coming out.

Is OneFlow® environmentally friendly?

Yes! OneFlow® is actually considered green for various different reasons. The first most basic reason is that pipework and machinery that is not affected by lime scale build-up is more efficient and economical to run.

Another factor is that OneFlow® requires no electricity. Water softeners are reliant on electricity for their basic running and also their regeneration cycles.

OneFlow® dramatically reduces water consumption and wastage in comparison to the alternative method of water softening. This is because it doesn’t discharge or go through any kind of backwash cycle unlike water softening.

OneFlow® requires no chemical dosing or salt to perform.

Is OneFlow® economical?

For many of the reasons above, OneFlow® is deemed to be very economical. The OneFlow® media is also cheaper to purchase than other alternatives.

Is water safe to drink after OneFlow® treatment?

Yes! As previously mentioned, if the water is potable going in, it will be coming out. The active ingredients in OneFlow® are safe for human consumption and do not have any effect on colour taste and odour.

Does OneFlow® require replacement?

This depends what method of application you are using. For cartridge filters, annual replacement is more than sufficient. For tank based systems, replacement is not required for three years.

Calcium scale in pipes and plumbing equipment often increases energy costs and can lead to expensive repairs to appliances such as hot water heaters, ice machines, coffee makers, and dishwashers. On the other hand, calcium is important to human health, and supplements are often recommended if this important mineral is totally reduced or absent from a person’s diet.

Water quality professionals now have a revolutionary product for fighting scale and retaining the benefits of calcium in water: OneFlow®. With OneFlow there’s no salt, no backwash, no scale, and no electricity to worry about. This environmentally-friendly solution eliminates sodium discharge by using Template Assisted Crystallization (TAC) technology to transform dissolved hardness minerals into harmless, inactive microscopic crystal particles. These particles make their way through plumbing systems without latching on to pipes, inside fixtures, valves, or heating elements. Scientifically tested for performance, OneFlow provides scale control results backed by years of successful field applications and independent studies. OneFlow from Watts is the intelligent choice in scale prevention.


  • No salt or chemicals required
  • Economical and efficient
  • Upflow design for better flow rates
  • No backwashing and zero discharge
  • Virtually maintenance free
  • Consistent scale control performance
  • Wide range of commercial applications
  • Uses environmentally friendly “green” technology
  • Long-lasting media needs no regeneration


  • Eliminates the need for scale prevention chemicals or salt
  • Eliminates de-scaling chemical costs
  • Reduces labor costs and downtime
  • Increases operating efficiencies
  • Extends life of capital equipment
  • Reverses existing scale problems
  • Provides immediate ROI through energy savings

OneFlow® Anti-Scale System

The OneFlow® Anti-Scale System provides protection from scale formation on internal and external plumbing surfaces. The OneFlow® system may be installed at the point-of-
entry to a building to treat both hot* and cold water, or it can be located directly before a water heater, boiler, or other hot water-using device that requires protection from the ill effects of hard water.

OneFlow® prevents scale by transforming dissolved hardness minerals into harmless, inactive microscopic crystal particles, as water travels through the media filled tank. These precipitated micro-crystals stay suspended in the water and are passed to a drain, thereby having a greatly reduced ability to react negatively like dissolved hardness minerals do. The system requires very little maintenance, no backwashing, no salt, and no electricity. Typical hardness problems, especially build-up of scale in pipes, water heaters, boilers and on fixtures are no longer a concern.

OneFlow® is not a water softener or a chemical additive (like anti-sealants or sequestrates). It is a scale prevention device with proven third party laboratory test data and years of successful residential and commercial applications. OneFlow® is the one water treatment device that effectively provides scale protection and is a great alternative to water softening (ion exchange) or scale sequestering chemicals.


Chemical-free scale prevention and protection – converts hardness minerals to harmless, inactive microscopic crystals making OneFlow. an effective alternative technology to a water softener for the prevention of scale due to water hardness.
Virtually maintenance free – No salt bags or other chemicals to constantly add.
No control valve, no electricity and no wastewater.
Uses environmentally friendly “green” technology.
Improves efficiency of all water using appliances – both hot** and cold.
Simple sizing & installation – all you need to know is pipe size and the peak flow rate.
Perfect system for towns or communities where water softeners are banned or restricted.
Manifold assemblies for easy installation of multi-tank, highflown applications (Can be operated in parallel for full-flow applications.)
OneFlow. does not remove minerals or add sodium to the water supply.
OneFlow. can be installed as pre-treatment to reverse osmosis (OneFlow. should be the last stage in treatment unless a point-of-use system is being used downstream.)
** For hot water applications where water temperature is 110°C to 140°C (43°C – 60°C), please see ES-OneFlow-HotWater

Commercial Systems are designed for long runs and high usage. Do not use where water is microbiologically unsafe or with water of unknown quality without adequate disinfection before or after the unit. System must be maintained according to manufacturer’s instructions.

Pre-Treatment for sediment , iron, hydrogen sulfide, manganese, hydrocarbons and copper may be required depending on conditions.

OneFlow® Application Practices

Systems using OneFlow® technology prevent hard water scale formation inside the plumbing system at influent hardness levels of 75 grains per gallon of calciUm carbonate and less. Due to variances in water chemistry, certain aesthetic conditions exterNal of the plumbing system may not be attained.

OneFlow® is designed for the treatment of potable water that meets the requirements of the current USEPA Safe Drinking Water Act. The addition of soaps, chemicals or cleaners, before or after the OneFlow treatment, may reverse its anti-scale treatment effects and/or create water with heavy residue or spotting potenTial. Any adverse conditions cause by the addition of soaps, chemicals or cleaners is the sole responsibility of the end user.

New copper lines need to passivated before placing unit into service. Copper usually originates from new copper plumbing upstream of the OneFlow® system. All new copper plumbing before the system should be allowed to passivate by operating under normal conditions for a periOd of four weeks prior to starting up the system. This will allow the copper surfaces to be fully flushed and develop a natural protective surface. To further minimiSe any problems with excess copper, avoid applying excess flux on the inner surfaces of the pipe and use a low-corrosivity, water-soluble flux listed under the ASTM B813 standard. OneFlow® is not designed for use on closed loop systems.

Usage and costs are annual. Assumes 15 grain water, 1 million gallons per month, 2800 grains/lb of salt, salt cost 0.12/lb delivered.

The £11363.77 annual (hard cost) saving above do not account for housekeeping and energy efficiencies (soft cost).

Caesars Windsor Hotel & Casino

Customer :

This four diamond hotel in downtown Windsor, Ontario with 758 guest rooms and a 100,000 square foot state of the art convention centre prides itself on providing an “essence of indulgence, comfort and luxury” in “masterfully appointed guest rooms and suites.”

Scope :

Provide scale control for 21 humidifiers that support one of two hotel towers and supply water to the hotel kitchen.

Challenge :

Prevent scale build up on Nortec ACS7W humidifiers from high (8 GPG) hardness levels in the city water.

Solution :

Watts OneFlow® Anti-Scale systems, Model #OF844-12×12 (144 GPM)

Results :

In a comparative analysis between humidifier treated with OneFlow® system and an equal capacity humidifier without, after 300 operating hours there was no scale build up on the heating elements and considerably less scale formation on the walls and bottom of the treated unit. Caesars Casino decided to install OneFlow® units in front of all 21 humidifiers in the west block of the building as well as the supply water for the kitchen, The OneFlow® system has eliminated water related scale issues and saved the customer money in both maintenance and energy costs.

Quisling Terrace Apartments

Customer :

60 unit apartment residance in Mansion Hill district of Madison, WI

Scope :

Scale prevention system to protect domestic water heaters, valves and plumbing fixtures within a historic apartment complex.

Challenge :

To prevent damage of equipment from extremely high (30 GPG) hardness levels in Madison City Water.

Solution :

Watts OneFlow® Anti-Scale system, Model #OF1465-50 x2 (100 GPM)

Results :

OneFlow® protects water heaters, valves and fixtures from hard water scale build up where the previously installed scale inhibiting device has failed.

Tucked away in the Mansion Hill District of Madison, Wisconsin, the Quisling Terrace Apartments boasts a classic exterior and classy interior, describing itself to prospective residents as “a home you will be proud of.” In order to ensure the class and pride extended to the quality of its water, the apartment complex set out in 2007 to find a water quality solution the would protect domestic water heaters, valves and plumbing fixtures from the effects of extreme hard water.

A familiar Madison landmark built in 1980, the Quisling Terrace was originally a house, but was successfully converted into an apartment building and then a mid century health clinic. In 2000 it was renovated back into a sixty unit affordable housing apartment building. Though the building did include the original scale inhibiting device, it was not equal to the task of dealing with the 30 grains per gallon of hard water minerals. Though it was compact in size and low cost, the system did not effectively stop scale build up and corrosion. The complex had to replace eleven water heaters over 7 years and had numerous complaints from residents about lime and scale on fixtures.

Looking for a similar low cost, compact solution that would be effective in preventing scale, manager Kat Gallagher chose the OneFlow® Scale Control System. Overnight the complaints from tenants ceased. So, too did the maintenance and service requirements. Further, the system has the desired small footprint and does not use any expensive or high maintenance chemicals. It has operated continuously and without complaint since its installation in December 2007.

Crowne Plaza La Concha

Customer :

Crowne Plaza La Concha, located on Duvall St. in the heart of Key West, was built in 1926. Rich in history, it has been home to famous writers and jet setters. Today the popular hotel books rooms year-round at 90% of capacity.

Scope :

The hotel’s goal was to control scale in its seven-story hotel, including 160 guest rooms, pool, laundry facilities, three bars and a restaurant.

Challenge :

Reduce unscheduled maintenance and increase the life of capital equipment.

Solution :

Watts OneFlow® Anti-Scale Systems, Model # OF1665-75 x4 (300 GPM).

Results :

In addition to a 90% space footprint reduction, the hotel has reported no visible scale in fixtures and capital equipment since its installation in 2007.

Keeping water flowing freely and safely for guests is a priority for any hotel, but for the Crowne Plaza La Concha, in the heart of Florida’s Key West, hard water and scale buildup were serious concerns. Key West receives the bulk of its water from a pipeline which pumps notoriously hard water from the Biscayne Aquifer in the Florida Everglades. “You could visibly see the scale,” says Chief Engineer Daniel Betlewicz, “On the sinks, but especially in the back of the house…and in the laundry area where water was used on a daily basis.” Maintenance on capital equipment, such as water heaters, had to be done regularly, and opening them up, the La Concha engineers would find clumps of scale build up that needed to be scraped out, wearing on and potentially damaging equipment over the long-term.

Betlewicz describes the decision to go with OneFlow from Watts as a “no-brainer”. In addition to it scale control and low water waste, it was just the compact solution the retrofit needed. “This system actually fits my boiler room,” the Chief Engineer explains. “We’ve got limited space because the building is old. This system is very compact. It’s just four tubes…a perfect fit.”

Five years later the system is viewed as a huge success, saving La Concha time and money. “This is a good solution for every hotel,” says Betlewicz. “No one calls me for any scale problems, anymore. A couple months ago, we had to replace the motor on one of our domestic pumps, and when the contractors took the system apart it showed no sign of scale inside, at all. Even the contractors were surprised, you know, cause there’s usually something. And we have no problem with water heaters or anything. We were pretty happy because I was expecting something, you know…and it was clean.”

Embassy Suites Hotel

Customer :

The Embassy Suites Napa Valley hotel is located in the heart of Napa and Sonoma Wine Country, conveniently located near historic downtown Napa.

Scope :

The 205-room hotel, situated on seven acres of beautifully landscaped grounds, is also home to the Grille 29 Napa restaurant.

Challenge :

Embassy Suites needed to address moderately high (5 GPG) hardness levels in their water. Their existing water softener for the hot water supply failed and needed to be replaced. The hotel was looking for a more economical solution to replace their water treatment system.

Solution :

Watts OneFlow® Anti-Scale Systems, Model # OF1665-75 x3 (225 GPM total).

Results :

After two months of OneFlow service, the hotel was already happy with its cost savings. The Chief Engineer also reported guest room sinks and faucets with visibly less scale build up. In addition, a boiler inspection report read, “No scale or any other types of deposits on internals of heat exchanger.”

Anti-Scale Systems

Salt Free water conditioning in the form of an Anti-Scale System uses a process method called Template Assisted Crystallisation (TAC) this process is where hardness minerals found within hard water are transformed into harmless, inactive microscopic crystal particles as water travels through the media. The crystal particles stay suspended within the water and are then passed to drain.

Anti-Scale Systems require very little maintenance, no electricity, no backwashing and no salt. Anti Scale systems are able to treat hot or cold water supplies and provide protection from the negative effects of hard water.

Need Help?

See below for One Flow features and case studies. For further information please contact us on
01629 363311

we are more than happy to help.