Frequently Asked Questions

Find the answers to some common questions about UV Disinfection and VIQUA Water Filters

Choosing and installing your system

Yes, we recommend all customers to follow the steps outlined in the Owner’s Manual and disinfect the pipe works by using chlorine. This step is important to do also in newly built houses with new water pipes to get rid of any dirt and bacterias that could have entered the system during the installation and construction.

Yes you can. However, in many areas of Thailand, well-water means hard water or a lot of iron, manganese or other substances in the water. In these cases we always recommend our customers to speak to us, our local partner or another local water treatment company first to get accurate information about water quality in the local area and advice on whether additional treatment is needed before installing the system.

No.The systems can be installed without a water pump if the mains water pressure is high enough in your area. However, most of our customers already have a pump installed or choose to install one to get better water pressure in the house.

Yes, but it is important to protect it from rain and direct sunlight.

No. UV Systems are designed with correctly sized inlet/outlet for the specific application.

VIQUA offers different models of systems to suit the different water flow demands of our customers. For example, our Whole House Systems ranges in capacity between 40-70 liters per minute and our Point of Use systems ranges between 7-24 liters per minute.

The size you need depends on the size of your home (how many bathrooms, kitchens, showers etc.) and the size of your family. As a reference a bathroom tap typically have a flow rate of 4-8 l/min and shower head between 10-15 l/min.

If you have a water pump installed it is good to determine the maximum flow rate of the water pump to then determine the VIQUA system best suited to that flow rate.

It is very important to not undersize the UV system, since a flow rate that exceeds the max capacity of the UV-system means that the water will not get enough exposure to UV-light needed to ensure adequate disinfection. If in doubt, it is always better to choose the next largest size of UV-system.

UV Water Disinfection

No. UV Systems are designed with correctly sized inlet/outlet for the specific application.

No, not at all. Nothing is added to the water and it does not change the taste or odour of the water. If you choose to install a system complete with pre-filtration, the carbon filter helps to remove any unwanted taste or odour from the water. In some rare circumstances, untreated sulphur odour can become more noticeable after UV treatment.

UV systems are very economical. A typical Whole Home System from VIQUA uses the same power as a 40-Watt light bulb.

Ultraviolet disinfection is an very effective way to get rid of microbiological contamination in water. However, microbes have to be exposed to UV-C light in the right amounts in order for the water to be effectively disinfected.

Water quality plays a major role in how much UV is passing through it. This is called UVT, or UV Transmission. In order for the appropriate amount of UV-C light to reach microbes to disinfect water, the UVT of the water has to be ideal. Low UVT occurs when there are organic molecules or minerals in the water that absorb or scatter the UV light, allowing microbes to pass through the UV system without ever being exposed to germicidal UV-C.

Because of these pre-treatment requirements, UV is not a stand-alone technology. Basic tap water generally comes out at 85-95% UVT.

With essentially all types of UV treatment, it’s recommended that the UV system be preceded by a 5 micron filter. UV pre-treatment will make your water taste and smell better and ensures that your UV system is working at maximum efficiency to protect you and your family 24/7.

Our Whole House Systems and Point of Use Systems are complete units that includes pre-filtration by using a sediment filter followed by a carbon filter which the water will pass before reaching the UV-chamber.

Some of our customers in Thailand with very bad water quality choose to install a sand or multi-media filter before the VIQUA system to take care of bigger particles and dirt in the water.

We distribute 3 types of systems in Thailand.

Whole House Systems

A Point of Entry System complete with pre-filtration plumbed straight in to your water line. This gives you safe, disinfected water straight from any outlet or tap in the house. Basically safe drinking water everywhere in your home.

Point-of-use systems

A smaller system complete with pre-filtration that can be installed anywhere in or outside your home to provide safe, disinfected water for a single tap and maybe also a refrigerator with ice-maker or a coffee machine depending on the capacity of the system. This system can be installed under the kitchen sink and used with your existing kitchen tap without the need for a separate “drinking water tap”.

Stand-alone UV Systems

This is a UV disinfection system without any pre-filtration that can be installed anywhere in or outside your home to disinfect your water. Maybe you already have your own pre-filtration and only want to add UV-disinfection. Then a stand-alone UV-system is what you are looking for.

The ultraviolet (UV) treatment process is an extremely quick physical process. Ultraviolet light mutates and/or degrades DNA. DNA (or deoxyribonucleic acid) is the part of the cell that gives an organism its instructions on how to function and reproduce.

When the DNA is damaged, the organism becomes unable to function because its “instructions” are garbled or missing. An organism that has no instructions cannot function and reproduce, and cannot cause infection. It is rendered harmless and eventually dies.

In the UV disinfection process, water is purified as it runs through a stainless steel chamber (also called a “reactor”) that contains a special UV- producing lamp. As the water flows past the lamp, the microbes in the water receive a lethal dose of UV. The water is then safe to drink.

UV disinfection typically offers a 4-log reduction (99.99%) for both bacteria and most viruses. UV is more effective than chemical disinfection processes at destroying a wide range of viruses.

Water Quality

Yes, absolutely. In fact, municipal water in Thailand is generally perfectly safe to drink when it leaves the water treatment facility. The problem is the vast network of water pipes with often poor quality that the water has to pass before it reaches our homes. This is where the water easily get contaminated by bacteria and harmful microbes.

With a UV-disinfection system that effectively eliminates these contaminations, the water is then again perfectly safe to drink.



Municipalities work very hard to provide safe water for their customers. In some areas of Thailand, the water leaving the treatment plant is considered safe to drink. However, that water then moves through a vast distribution system that in many cases is aged and can lead to contaminations. The water that then reaches your home is often far from safe to drink. A UV Disinfection System gives you and your family peace of mind and is a very affordable insurance policy against the possibility of coming in contact with water contaminated with microbes.

Yes you can. However, in many areas of Thailand, well-water means hard water or a lot of iron, manganese or other substances in the water. In these cases we always recommend our customers to speak to us, our local partner or another local water treatment company first to get accurate information about water quality in the local area and advice on whether additional treatment is needed before installing the system.

No, not at all. Nothing is added to the water and it does not change the taste or odour of the water. If you choose to install a system complete with pre-filtration, the carbon filter helps to remove any unwanted taste or odour from the water. In some rare circumstances, untreated sulphur odour can become more noticeable after UV treatment.

Maintenance and Service

Over long periods of non-use, the water in the UV chamber will become warm due to the high operating temperature of the lamp. VIQUA UV systems are designed to avoid overheating. The UV chamber contains only a small volume of water and the temperature will cool quickly after opening the tap.

Yes. This is because the of the high operating temperature of the lamp and happens especially when there are long periods of non-use.

Our systems connects to a wall outlet like other electrical appliances. The systems should always be connected to a dedicated wall outlet protected by a GFI (ground fault interrupter) /RCD. In areas that experience significant power fluctuation, we recommend the use of a surge protector.

The system should be left on even if you are not using it for periods shorter than 3 weeks. Turning the system on and off regularly can disturb and have a negative impact on the UV-lamp. When you leave the system on, you are also sure that no contaminated water flows through the system and your pipes while you are not using it. However, some of our customers choose to unplug their systems when they are not using it for a period of more than 3 weeks. This can be done to extend the lifetime of the UV lamp. In any case where your VIQUA system will be drained from water, the system needs to be turned off.

A UV-lamp has a lifetime of 365 days of continuous use. After that, the UV-light intensity starts to diminish and it is no longer able to effectively disinfect the water. It is very important to replace the UV-lamp every 365 days to ensure that your water is still safe to drink. Our Whole Home Systems have a sophisticated control unit that will let you know the status of the system. It tells you how many days are left until lamp replacement and will give you a visual and audible alarm when the the lamp life is due to replacement.

UV lamps have a useful life of about 9000 hours (approximately 365 days) which means that in most cases annual replacement is required. It is very important to replace the UV-lamp after 9000 hours, since there may not be enough UV energy to provide adequate disinfection after that.

There is also a quartz sleeve that surrounds the UV lamp which must be kept free from hardness or iron deposits that would have a negative impact on the UV disinfection process. Under normal conditions the sleeve can be cleaned when doing the annual lamp replacement.

For our Whole House and Point of Use Systems that comes complete with pre-filters (sediment and carbon) maintenance includes replacing these when they get dirty or clogged. Replacement interval for pre-filters depends on usage and water quality in your local area and can vary from between 5-12 months.

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Official Thailand Distributor of VIQUA Water Filters

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