Frequently Asked Questions  

At GWP, we want to inform you correctly and as completely as possible about our products and services.
We therefore do everything we can to answer as many questions as possible. If you still cannot find an answer to your question here, please be sure to  let us know. We will then see if we can include this question in the list below.

Limescale and corrosion


Hard water is water that has high concentrations of calcium and magnesium minerals. Hardness itself is expressed in French degrees, or sometimes the German equivalent is used. Regional soil conditions determine the amount of calcium and magnesium minerals in drinking water. If this concentration is high, the water is said to be hard and you may experience problems with limescale when the water is heated.  Limescale starts to form at levels as low as 5 °F. On average, tap water has a hardness of 15 °F. 

Specifically, 1 °F means that there is 10 mg of calcium present in 1 litre of water. So if you consume 150 m3 of water annually at a hardness of 10 °F (100 mg of calcium), this will give you over 15 kg of calcium per year.

Not at all. Calcium (and magnesium) minerals are very important for good health. It is the most important mineral in the human body and is absolutely essential. That is why our drinking water companies always retain a certain amount of these minerals in the water.

Unlike water softeners that remove calcium and magnesium from the water, OPTICALC retains these minerals in the water and only prevents them from causing damage in the form of limescale.

The hardness of the water varies among municipalities. This is logical since the soil conditions determine the amount of calcium and magnesium minerals, and this is different in each municipality.

You can easily find this out via the website of your regional water company.   

Calcium in water causes a great deal of inconvenience.  When you heat water, the calcium particles dissolve less easily and form hard-to-remove limescale.  In water boilers and water heaters, this is called boiler scale. These lime deposits cause a great deal of inconvenience: the most problematic is the layer of limescale that settles on the inside of water pipes or on heat exchangers in boilers or dishwashers. This results in loss of efficiency, blocked pipes and wear on taps, washbasins and shower walls.

Most people are aware that limescale can cause a lot of damage. What most of us pay far less attention to is the very gradual loss of efficiency that this causes. Even with minimal limescale deposits on heat exchangers, you will soon consume a lot more energy.

If you would like to know more about the efficiency losses in combi boilers, we refer you to the well-known  Batelle study which has done extensive research on this subject.

That depends on the hardness of your water, of course. But it does happen very quickly. A large-scale study in the USA shows that, at a hardness of 45°F (or 25°D), the initial adverse effects of limescale can be seen on taps and in pipes after only 2 to 3 months. After 18 months, showerheads have been found to have lost 75% of their flow rate! Continuous flow boilers fail after as little as 1.6 years as a result of limescale deposits. If you are aware that in Belgium and the Netherlands the average hardness is 15°F, you already have an increased chance of initial problems with your boilers after 4 years due to limescale.

It is therefore important to tackle limescale from the outset  not only provides protection against limescale, but also dissolves and removes existing limescale.

What is corrosion?

Corrosion can take many different forms but most people know it as rust.  Corrosion is a considerable problem worldwide.  Every year, corrosion causes damage worth 17.5 billion euros. Corrosion is a natural, electrochemical process that easily occurs in humid and warm environments. It is precisely for this reason that it also causes health and safety issues in a domestic plumbing system.

What are the effects of corrosion?  

Corrosion occurs in both ferrous and non-ferrous materials and even in plastics. Corrosion causes the materials to become porous. This causes crumbling particles to enter the drinking water, which gives the water a brown colour. In lead water pipes in particular, this can lead to health problems as a result of lead contamination. In addition, these suspended particles in the water cause irreparable damage to plumbing appliances, such as dishwashers, boilers, and so forth. The inside of the boiler cylinder and pipes are particularly susceptible to rust.

Dankzij de OPTICALC wordt er een dunne beschermingsfilm aangebracht aan de binnenkant van de leidingen en boilers en op verwarmingselementen. Deze beschermingslaag voorkomt corrosie en bijgevolg ook de schadelijke gevolgen ervan.

What are drinking water companies doing to combat limescale and corrosion?

Our drinking water companies do everything they can to provide safe and healthy drinking water. By adding phosphate, for example, they ensure that corrosion is prevented in order to reduce the suspended rust particles in the water. When it comes to water hardness, things are a little more complicated. Although they already soften the water in many places, they will always provide drinking water with a hardness that will not and must not fall below 15 °F. This is because of statutory requirements to keep healthful minerals like calcium and magnesium in the drinking water. Unfortunately, limescale starts to form at levels as low as 5 °F.

  

Does lead contamination still occur? 

Lead contamination occurs when lead pipes release lead particles into the water as a result of corrosion. Although this problem has decreased significantly in recent years, it has been found that 1 in 100 houses are still struggling with this problem. Older homes in particular may still have lead water pipes, often also because they are difficult to remove or replace.

 

Opticalc


OPTICALC has a dual effect and protects against both limescale and corrosion. In addition, the phosphate minerals cause the existing limescale to gradually dissolve. A unique dosing system in the cartridge allows a controlled and precise phosphate dose of 3 mg/l (on average) to be added to the water. In addition, using food-grade phosphate powder – rather than crystals or liquid phosphate as is the case with many other solutions – prevents excessive concentrations in the case of standing water, for example

The addition of phosphate minerals to tap water serves 3 important functions :

1) Phosphates naturally bind with the calcium minerals present and prevent them from developing into lime crystals, which are responsible for limescale. Important: this means the healthful calcium is not removed from the water, but only neutralised.

2) In addition, phosphates cause the existing limescale to gradually dissolve. This takes place over months, however, not days. Nature always needs to be allowed time.

3) Phosphates cause a thin protective film to form along the inside of water pipes and boilers, and on heating elements. This protective layer prevents corrosion from occurring and therefore possible lead contamination.

Unlike salt solutions, phosphates therefore not only have a preventative effect but also promote recovery.

Yes, that's right. You do this by registering your device in this way as soon as you start using it. deze manier van zodra je hem in gebruik neemt.

From that moment on, you benefit from a 10-year guarantee on the dosing device. The only condition is that you always replace your dosage cartridges as soon as the built-in audible warning is activated.

 The guarantee extension applies to all parts of the    device provided that the damage or defect is not the result of malicious intent and the device was fitted correctly. The extension does not apply to the dosing cartridges. 

The replacement parts will be sent to you free of charge.

The guarantee extension covers both items purchased directly from the webshop and items purchased from a plumber or maintenance technician.

   should always be connected to the cold water supply. There are 2 places where you can fit it:


1) Just downstream from the water meter: this protects all pipes, taps and appliances in your home.

2) Just upstream from the boiler: this will only protect your boiler and the appliances, taps and pipes that come after it.

We have known about phosphate minerals as an efficient solution against limescale and corrosion since the beginning of the last century. So this is certainly not new and its efficiency is obvious.

What makes    so innovative is its easy installation, ease of use – including when it's time to replace the cartridge – and highly controlled dosing. OPTICALC is supported by several patents granted worldwide.

Yes, you can. Whether the pipes are made of steel, copper or plastic makes no difference to    .

Unlike water softeners, it is not necessary to carry out extensive, costly maintenance every year. As with other plumbing installations, you just check from time to time that everything is still working properly. It is only important to replace the cartridge when empty to ensure you enjoy the full protection of   .

OPTICALC cartridges can be ordered easily from our webshop or from your plumber or service technician.webshop or from your plumber or service technician.

The ticking sound is    built-in audible warning.
This indicates that the cartridge is almost empty and needs to be replaced. You should do this as soon as possible to enjoy the full protection of OPTICALC.

OPTICALC cartridges can be ordered easily from our webshop or from your plumber or service technician.webshop of via je je loodgieter of onderhoudstechnicus.

The ticking sound indicates that your dosing cartridge is empty and it will not provide any more protection. You fix this by replacing your empty cartridge with a new one. 

OPTICALC cartridges can be ordered easily from our webshop or from your plumber or service technician.webshop of via je je loodgieter of onderhoudstechnicus.

Even more so. OPTICALCnot only provides protection but also restores your system by gradually dissolving the limescale. OPTICALC also provides double protection. The added phosphate minerals bind with the calcium and magnesium minerals to stop them from developing into limescale. In addition, the phosphates also cause a thin film to develop along the inside of the pipes, the boiler and on the heating elements, therefore providing protection against corrosion. So you get double the protection.

OPTICALC is therefore a genuine alternative to the conventional and expensive water softener.

You certainly don't have to get rid of your existing water softener if you don't want to. Always fit the OPTICALC directly downstream from the water softener. This ensures protection against corrosion (which the water softener does not do) and you can also adjust your water softener so that it needs to use less salt to have the same effect.

The protection provided by   is not permanent. This is only logical, given the constant flow of fresh, untreated water. This is why it is important to replace the cartridges as soon as they are empty.

Numerous phosphate installations worldwide have shown us that the phosphate minerals do indeed dissolve the existing limescale bit by bit. This takes place over months, however, not days. Nature always needs to be allowed time.

No   uses phosphate minerals, which bind with the calcium and magnesium minerals to stop them from developing into limescale. So calcium and magnesium are not removed from the drinking water. Due to the presence of calcium, tap water retains its positive effect on our health but no longer causes any inconvenience.

Limescale forms in hot water. Phosphate minerals work best at temperatures between 55 °C and 85 °C. Apart from the kettle and the occasional boil wash, there are hardly any appliances that heat above 85°C. Your boiler is usually set to about 65 °C and the dishwasher only reaches 70 °C or sometimes even 80 °C when rinsing.

Certainly !   is designed so that it requires no additional couplings or electricity or water supply. In addition, OPTICALC is very compact and light so no anchoring in the wall is required. As it is important that the installation is done correctly, we always recommend contacting your plumber.

   is environmentally friendly for 3 reasons :

1) OPTICALC OPTICALC prevents limescale formation on heat exchangers and ensures that there is no loss of efficiency. This may result in an energy saving of 20%! 

2) OPTICALCdoes not waste any rinse water for regeneration and uses no electricity

3)Phosphate minerals are reusable. The phosphates that end up in the wastewater are recovered by the drinking water companies and processed into struvite, an ideal fertiliser for agriculture. Plants need these minerals to grow and they absorb them from the soil. In turn, these plants provide food for humans and animals, who release the phosphates into the wastewater through their urine.

No. The key difference compared with water softeners is that    does not remove the healthful calcium and magnesium minerals from the water, but only neutralises them in order to prevent them caking together and causing problems. This means that the water will not become softer.

Yes it does. As the phosphate minerals added by     form a thin film on the inside of the boiler, the lifespan of the magnesium anode is extended.

Opticalc cartridges


The white powder inside the cartridge is made of food-grade phosphate minerals that provide protection against limescale and corrosion. If you would like to know all about these minerals, take a look at the FAQ on Phosphate minerals. 

OPTICALC  has a built-in audible warning that starts ticking when your cartridge is almost empty. If you don't have any cartridges left, be sure to order them from our  webshop  . 

This depends on the location of the     the number of people in your household, and the amount of water you use annually. For an average family of 4 people using an average of 120 to 150 m3 of water per year, you will only need 2 to 3 cartridges per year. So you will need to replace them every 4 to 6 months.

If the OPTICALC is positioned directly upstream from your boiler, consumption will be lower.

Replacing the cartridge could not be simpler. Be sure to take a look at our  user guide page pagina. 

Step 1: Turn the orange shut-off valve to "bypass". Don't worry, your water will carry on flowing, so you're certainly not shutting down your entire water supply.

Step 2: Unscrew the cartridge casing. Note that there may be some water left in the device..

Step 3: Take out the empty cartridge and insert a full cartridge

Step 4: Screw the cartridge casing back on. Don't screw it on too tightly! As soon as you feel resistance, that's enough..

Step 5: Turn the orange shut-off valve to "Open". The water will flow through the OPTICALC again..


OPTICALC cartridges can be ordered easily from our   webshop  or from your plumber or service technician.

We make sure that every cartridge that leaves us is of the highest quality. The white powder in the cartridge is made of food-grade phosphate minerals, a certain amount of which ends up in your tap water. Whether the powder looks like 1 block, like 2 blocks, or is a bit crumbled, it does not matter – the effect is still exactly as it should be! However, when your cartridge is empty, your Opticalc is no longer guaranteed to work and you will need to order a new cartridge. This can be done easily via our webshop.

Phosphate minerals


Phosphates are compounds of the mineral phosphorus and oxygen, which enables them to be absorbed by living organisms. Phosphate is a natural mineral and is necessary for life on Earth. Without this mineral, plants, animals and humans cannot survive. In humans, it is the most important mineral present in the body after calcium. It is essential for our DNA and cell structure, teeth, bones, and proper functioning of our kidneys. It is sometimes referred to as "the all-regulating mineral". 

Phosphate minerals are naturally present in almost all of our food products. Important sources of phosphate include, dairy products, eggs, meat, fish, legumes, and wholegrain products.

It is also possible to extract these minerals from phosphorus ores. Marine animals naturally store phosphates in their shells and bones. The remains of these animals form phosphorus deposits in the soil millions of years later. These are mainly found in Morocco, China, South Africa and the United States. After a purification process, phosphate minerals are obtained, which are used as a fertiliser in agriculture and as a food additive in the food industry. It is this food-grade form that is used in OPTICALC.   

Absolutely.  The phosphate mineral used by GWP is known as polyphosphate, a widely used food additive in the food industry, and is 100% safe for consumption. Numerous health organisations worldwide, including the US Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) expressly recognise that their use is suitable for consumption and does not pose a risk to food safety.

Yes, this mineral is completely odourless and tasteless and behaves in exactly the same way as its natural variant in food products such as milk, meat, fish, nuts, and wholemeal cereals.

Phosphate minerals are the second most important group of minerals in the human body after calcium.  Phosphate minerals ensure strong bones, healthy teeth, optimum digestion, and proper functioning of the kidneys. What is more, they have a positive effect on cognitive function and general growth and development. Phosphate minerals are therefore very important for development in children and young adults.


According to the Nordic Nutritia Recommendations from 2012, a child and adolescents need on average 700 mg/day, an adult 600 mg, and breastfeeding women as much as 900 mg. The addition of phosphate to drinking water from OPTICALC therefore contributes to the required daily phosphate intake.      

Absolutely. Phosphate minerals are recyclable naturally. Plants take in phosphates from the soil to grow and serve as food for humans and animals, which, in turn, excrete large amounts of phosphates via urine, at which point phosphates become a more important food source for plants.

Drinking water companies are an important link in this process. After all, our wastewater is full of phosphates as it includes our urine, among other things. Through phosphate recovery, they recycle these phosphate minerals in the form of struvite, which can be reused in agriculture. This reduces the need for extraction of phosphate ores, which in turn has a positive impact on the environment.

The Netherlands, for example, extracts up to 12,000 metric tonnes of phosphorus from domestic wastewater every year, which accounts for almost 60% of the annual phosphorus requirements in the country.

The addition of phosphate minerals to tap water serves 3 important functions :

1) Phosphates naturally bind with the calcium minerals present and prevent them from developing into lime crystals, which are responsible for limescale. Important: ultra-healthful calcium is not removed from the water, but only neutralised.

2) In addition, phosphates cause the existing limescale to gradually dissolve. This takes place over months, however, not days. Nature always needs to be allowed time.

3) Phosphates cause a thin protective film to form along the inside of water pipes and boilers, and on heating elements. This protective layer prevents corrosion from occurring and therefore lead contamination.

Unlike salt solutions, phosphates therefore not only have a preventative effect but also promote recovery.

No .Unlike with water softeners, the all-important calcium and magnesium minerals are retained and not removed and replaced by sodium. Due to the presence of calcium, tap water retains its positive effect on our health but no longer causes any inconvenience.

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