Frequently Asked Questions

If you would like to know more about our unique water disinfection systems and technologies, take a look at our FAQs below to see how our British-built systems can benefit you. Whether you want to learn about our sustainable Hyprolyser® electrochlorination systems or you’re interested in the benefits of our efficient chloriDOS® iOX® chlorine dioxide systems, you can discover a range of insightful information below.

Can’t find the answer you were looking for? Get in touch with us today to speak to our knowledgeable team.

Universal/General FAQs for Gaffey in-situ systems:

I want to chemically dose to multiple points in my facility, how many generators do I need?

You generally only need one generator! The generated solution for both chloriDOS and Hyprolysers is stored inside a tank which allows numerous pumps to dose from it to your application where location conditions allow.

A by-product of electrochlorination is Hydrogen, does this mean the installation room falls under ATEX regulations?

The Hyprolyser® family has been designed with safety as a priority and have been reviewed for Hazardous Area Classification. This review concludes that the Hyprolyser® does not create any external zones and therefor falls outside of ATEX & DSEAR directives.  Always carry out your own site HAZOP risk assessment.

I want to buy a Gaffey in-situ generator, how do I install it?

We have developed a network of service & installation partners in the UK and overseas that can look after the installation and maintenance of Gaffey equipment. We can also provide training either on site or at our factory in Accrington.   

Do Gaffey in-situ generators require a circulation loop to dose the NaClO/ClO2?

Gaffey in-situ generators are off-line, which means all you need is a metering pump of your choice to dose the product from storage tank to your injection point/process.

Is the Hyprolyser® suitable for use in drinking water applications?

The Hyprolyser® Standard product range is approved under regulation 31 of the Water Supply (Water Quality) Regulations 2000 for use in the public water supply in the UK. 

Are Gaffey in-situ generators comply with the Biocidal Products Regulation (BPR, Regulation (EU) 528/2012)?

All electrochlorination systems placed on the market comply with requirements under Article 95 of the BPR in EU/GB.  All chloriDOS iOX systems fall outside the scope of BPR as they are interpreted and classed as blending/dosing equipment.

What reagents can I use with the chloriDOS® iOX®?

The iOX® can be configured in our factory for use with many different chemical reagents and concentrations depending on your favoured chemistry or availability of chemicals. Speak to one of our technical team today or leave an enquiry to find out more.

What size Hyprolyser®/chloriDOS® do I need?

To size a generator correctly you need to know your peak demand and overall daily demand of chlorine/chlorine dioxide. The generators have product tanks which stores the NaClO/ClO2 ready for use by correctly sized dosing pumps during the peak demand.  This allows a smaller hourly output generator which refills the correctly sized product tank volume throughout the 24hr day.

Does the Hyprolyser® require frequent maintenance and adjustments?

Once installed and commissioned the Hyprolyser® needs little remedial maintenance. All the operator needs to do is top up the salt saturator, fill in the operators log and check the hardness of the water. With there being no brine pumps along with the units being built to be simple and reliable, it means no adjustments by the operator are necessary.

I have heard ClO2 is dangerous and leaves excess acid and chlorite in the water, is this true?

The chloriDOS® iOX® mitigates the operational safety issues and overdosing of reagents that generators have become renowned for by:

  • Using patented vacuum batching technology so no chemical is ever under positive pressure.
  • Using volumetric measuring of chemicals with detailed process alarms to stop underdosing/overdosing of acid or chlorite.
  • Allowing chemicals to be stored safely over 50m away from the generator and each other due to the unique vacuum batching method.
  • Not using dosing pumps to inject reagents into a reactor. 
  • Having >99% process efficiency. This also greatly reduces consumption of reagents and therefore the total cost of operation. 

Reasons why should I invest in an electrochlorinator instead of bulk Sodium Hypochlorite storage?

  • H&S for operators – No chemical deliveries are required, only salt. 
  • Cost – Commercial Hypochlorite is considerably more expensive over time than the salt, water and energy required to produce electrolytic chlorine.
  • Quality of product – Fresh solution is generated every day, so the chlorine concentration is always stable with little chlorates compared to commercial Sodium Hypochlorite being stored for longer periods of time.
  • pH – Electrolytic chlorine is lower in pH than commercial hypochlorite, this saves time and money on unnecessary pH correction. 
  • Off gassing -Electrolytic chlorine does not off gas so creates no issues for priming interventions of metering pumps.

Hyprolyser® Electrochlorination FAQ for commercial swimming pool applications:

What is Electrochlorination?

Electrochlorination is a term which is generally used to describe the process of generating a chlorine laden solution by passing an electrical current through a solution of salt and water. There are several distinctly different electrochlorination methods available, suited to different markets or applications. Here, we focus on the “undivided cell” off-line method used in Hyprolyser systems. We hope the following information will help in providing answers to some of the most important and frequently asked questions which often arise when   electrochlorination technology is being considered for commercial swimming pools.    

Is Electrochlorination a proven and reliable technology?

Electrochlorination has been commonly used since the late 1940’s as a method of providing chlorine for drinking water, swimming pool disinfection and many industrial and food processing applications. Over the past decade or so the advancement of DC power supply technology and electrode coating techniques has allowed the electrochlorination method to become much more compact, efficient and affordable. It is now widely used throughout the world and, due to its inherent safety, in many countries electrochlorination is becoming established as the method of choice when replacing chlorine gas or hypochlorite systems.

Does the Hyprolyser® have to be integrated into a swimming pool circulation?

The Hyprolyser® is not an in-line electrochlorination system. Being offline has significant advantages some of which are:

  • Chlorine generated is purer.
  • There is always buffer storage in the Hyprolysers® product tank.
  • Salt does not have to be added to the pool meaning less corrosion of pool equipment.

What is the difference between commercially produced and on-site generated sodium hypochlorite?

Commercially produced sodium hypochlorite normally contains 10-15% chlorine by weight, compared to typically between 0.5-0.8% for on-site generated products. Products containing less than 1% chlorine are generally classified as non-hazardous. With a much lower chlorine concentration the on-site generated product is very stable and, unlike commercially produced sodium hypochlorite, does not require the addition of sodium hydroxide (caustic soda) to help preserve the chlorine content, or anti-scale additives to prevent equipment blockages. This results in a chemically “clean” on-site generated product containing significantly fewer by-products and a much lower pH.  

If on-site generated product contains 0.6% chlorine, what else does it contain?

A litre of Hyprolyser generated hypochlorite contains: chlorine 6g, sodium chloride 13g, sodium hydroxide <1g,  chlorite 0.9g, chlorate 0.3g, sodium carbonate – trace. The remainder is water. The generated product is clear and pale green in colour with a slight chlorinous odour. The pH of the final product is typically 8.0-8.5, depending upon the pH of the source water used.

Hydrogen gas is produced as a by-product of electrochlorination. Does this create any health and safety risks?

Hyprolyser systems are designed with hydrogen safety management at the forefront. Although the amounts of hydrogen generated are relatively small, Hyprolyser systems are designed in accordance with UK DSEAR regulations so that the equipment/process has no safety impact on the space into which it is installed. Hyprolyser systems also have several failsafe features integrated as standard, including a hydrogen gas detection system which is designed to shut-down the Hyprolyser even if a trace amount of Hydrogen is detected in the atmosphere. Larger Hyprolyser systems are equipped with ventilation systems to dilute and safely expel Hydrogen to atmosphere outside of a building. These systems are so designed that hydrogen cannot accumulate in any part of the equipment during its operation.

Will the Hyprolyser system increase the TDS level in a commercial swimming pool?

Although on-site generated product may add slightly more sodium chloride to a pool than commercially produced hypochlorite, the significantly lower caustic content has less of an impact in increasing the pH, therefore less pH correction chemicals are required. In addition, the generated product does not contain any added phosphates (normally added to commercial products to reduce sediment and injector blockages) which promote the growth of algae and biofilm. If UV treatment is installed in a swimming pool then this will have a far greater impact in increasing TDS levels, due to the fact that some free chlorine is destroyed by UV with each pass through the treatment plant.  

Overall, the TDS balance will be very similar, or slightly less, than that of pools using commercially produced hypochlorite.  Any pool facility which operates normal backwashing and fresh water dilution practice will not experience any difficulty in controlling TDS levels. 

How safe is the liquid product produced by the Hyprolyser?

At 0.6% available chlorine content the on-site generated product is much safer to store and handle. Although it is still of sufficient strength to bleach clothing it does not cause instantaneous skin burn or serious eye damage if accidentally splashed.  It is also much less reactive in the event of accidental spillage onto contaminated floor surfaces or organic materials, in that it does not react violently to produce exothermic reactions like other commercial hypochlorites. Inherently better safety is afforded by the fact that on-site generated hypochlorite is produced daily, on demand, and does not need to be stockpiled in large quantities.

Even so, on-site generated product does contain chlorine and must therefore be stored and handled with respect and, in line with best practice, away from acids or other incompatible chemicals.  

On-site generated hypochlorite does not add any calcium to the pool. Will this mean the pool water will become corrosive?

The Pool Water Treatment Advisory Group recommends a minimum level of 75mg/l of calcium hardness to prevent corrosive water. More than 150mg/l will not provide additional benefit in protection against corrosion but will simply add to a higher acid demand (and an increase in TDS). The water supply in many areas of the UK is above the 75mg/l hardness level. Where calcium hardness levels need to be buffered, a quantity of calcium chloride can be added after a filter backwash or water replacement, either manually or via a simple pump/tank system. Using calcium hypochlorite just for the benefit of maintaining water hardness is an expensive way to manage balanced water and does not offer the option to avoid increasing water hardness when it is not needed!  

Are “salt” pools more damaging to the pool plant/ fabric?

Some methods of electrochlorination, such as “in-line” systems, require salt to be added directly to the pool, whereby some of the salt content is converted to chlorine on each pass through the electrolyser cell.  The higher levels of salt used in pools with in-line systems require the pool and its technical equipment and fittings to be able to withstand higher chloride levels. 

Off-line systems, such as the Hyprolyser, do not require salt to be added to the pool. Instead the salt is prepared into a brine solution which is fed directly to the Hyprolyser, which then generates hypochlorite and stores the generated product ready for dosing. Hyprolyser electrolysers are designed so that the maximum chlorine yield possible is obtained from the salt. When using off-line systems the low levels of salt transferred to the pool cannot be detected by taste.  Off line systems are generally much more efficient, powerful, and responsive to chlorine demand than in-line systems; this is the main reason that off-line systems are an ideal choice for commercial pools.

How can I compare the cost of on-site generated hypochlorite with my current chemical?

It is quite easy to work out with some basic information. Firstly, calculate your yearly chlorine consumption by using the following method:

For Sodium Hypochlorite 14%: Total litres used x 1.2 to convert to kilograms, multiplied by 14% = total yearly chlorine consumption in kg. Divide your annual cost of chemicals, including any pump/over, container or environmental charges, by the kg figure above to give you your cost per kg of pure chlorine. 

For calcium hypochlorite 70%: Total kg of calcium hypochlorite used per year x 70%= total yearly pure chlorine consumption in kg. Divide your annual cost for cal hypo, including any delivery, environmental or container disposal charges, by the total chlorine kg figure to give you your cost per kg of pure chlorine.

Hyprolyser:  For every kg of chlorine generated the Hyprolyser system will use 3.3-3.5kg of salt, 5kW of energy and 170 litres of water. At 2017 prices, salt is typically available at £6.00 net per 25kg (delivered), often less. You can calculate the costs for water and energy from your utility charges. At average market prices for salt, power and water, Hyprolyser produced chlorine costs around £1.70 per kg.      

Any item of dosing equipment will need some form of scheduled maintenance but, as true comparison, the cost of operating with your current chlorination method should also include annual expenditure on additional maintenance call-outs, the average annual cost of spare parts, personal protective equipment consumables and COSHH management time. 

With electrochlorination systems producing only 0.6% chlorine solution (non-hazardous), many of the traditional costs associated with health & safety/training, PPE consumables and COSHH management are significantly reduced. 

Does the Hyprolyser require a particular grade of salt?

Yes. The quality of sodium hypochlorite produced by the Hyprolyser depends on the raw materials used. Using the cheapest salt available can create operational problems and higher maintenance costs. Good quality food grade salt should be used, low in iron, calcium and magnesium. This type of salt is commonly available in most countries and from numerous suppliers. The specification of the required salt is described in the Hyprolyser Operation & Maintenance manual and is available on request. The salt supplier/manufacturers product specification data sheet (not the safety data sheet!) can be compared against the Hyprolyser salt specification table to ensure the correct grade is selected. In the European Union, salt used as a precursor for the purpose of generating active chlorine based disinfectants falls under the European Biocidal Products Regulation (EU) 528/2012, and as such should be sourced from a manufacturer or supplier on the ECHA Article 95 approved suppliers list. Your salt/chemicals supplier should be able to advise and assist you in complying with this regulation.

Will the electrochlorinator be able to keep up with peak demand?

Yes. A range of Hyprolyser systems is available to meet the chlorine demand of any size of facility. A correctly sized Hyprolyser system will be able to supply ample output of chlorine for your pool with headroom to spare.  When sizing a system for a new pool facility, care is taken to evaluate the expected bather load and other chlorine demands, such as UV treatment, water features etc. In existing pools the historical chlorine consumption, pool turnover and bather loading of the pool can be used to verify the correct size of Hyprolyser system required. It is also important to correctly size the chemical dosing pump/device capacity so that peak demand periods can be easily satisfied.  

Can one Hyprolyser system operate more than one pool?

Yes. A facility with multiple pools can often be provided for by a single, suitably sized Hyprolyser system. The product storage tank can also be sized to ensure all the pools in the facility have sufficient dosing capacity during peak periods of demand. 

Are equipment servicing costs higher than for traditional dosing systems?

A Hyprolyser® electrochlorinator is a very robust, high quality system designed with simplicity of operation and minimal maintenance as a priority. The average lifespan of the main components, the electrolyser and power-packs, is at least five years (typically seven years) when the correct grade of salt and routine maintenance is carried out as prescribed. Over the lifetime of the key components, servicing costs are similar or lower than for calcium hypochlorite feeder systems. However, as the hypochlorite produced by the Hyprolyser is not abrasive, scale or sediment forming, the level of maintenance or intervention by operating staff is greatly reduced. The need for cleaning/descaling of chemical injection points, normally a frequent and high risk task, is completely eliminated.

What effect does Hyprolyser have on water quality?

The liquid product generated by the Hyprolyser is clean and crystal clear. It contains no sediments or calcium salts and is very low in caustic content, therefore it has a lower impact on pH demand, creating additional chemical savings and making it easier to maintain chemically balanced water.  Unlike other commercially produced hypochlorites, it does not contain any phosphate based anti-scale additives (Calgon and similar additives).  Phosphate is known to promote algae and biofilm growth in swimming pools, so avoiding its use is good for water quality and hygiene. 

What effect does Hyprolyser have on bather comfort?

Any pool water treatment system using chlorine as a disinfectant will create some disinfection by-products, such as chloramines and nitrogen trichloride, which are the main source of irritation to bathers. Other potentially harmful by-product groups, such as THM’s (trihalomethanes), namely chloroform, are also created during the disinfection process through the reaction of chlorine with organic substances. Several European countries apply strict limits on the THM levels permitted in pools. It is known from several industry research papers that reducing the concentration of chlorine introduced at the injection point is an effective way of minimising strong reactions with organic pollutants, known to promote the formation of chloramines and THMs. Hyprolyser generated product at 0.6% chlorine is of a sufficiently low concentration to achieve this effect.   

The use of a salt based disinfection method also has other benefits; eye and skin irritation are less common, due to the fact that any residual sodium chloride completely dissolves in the pool water, producing softer water which is kinder to the skin and eyes. This comfort effect is well proven, particularly evident in saltwater pools using in-line electrochlorinators, and is one of the main reasons why the majority of the world’s domestic swimming pools use this simple method of chlorination.

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