Complete Guide to Home Water Filtration.

Or maybe that should read something like "consistently updated guide to water filtration"? This guide aims to cover the FAQ section with a bit more of an explanation. This should change as trends change and result in a colossal wall of text. It might be an idea to use the search function to quickly get to the part you need, or just call us. 

What is UV disinfection?

UV disinfection is most commonly water treatment with UV light. The process takes place when organic matter is exposed to light from the UV-C range of the light spectrum at 254nM. It's the most popular alternative to water treatment without Chlorine. Organisms (usually bacteria) will need a certain dosage of UV light to inactivate it and render it harmless. Dosage is worked out as the intensity of the UV light times the exposure time. In the UK we have a standard dose of 30mJ where most of the standard bacteria and viruses we come across will be sufficiently treated. Other regions of the world have varying levels of standard dosage but in general it will range from 25-50mJ.

 

Do UV water filters work?

As long as the system that you're using has been sized and installed correctly (you can put them in the wrong way around) and you keep them maintained properly then they're a tried and tested piece of equipment. They are becoming increasingly popular as consumers are more reluctant to buy, use and store chemicals on-site and UV systems are a great way to counter that.

In regards to installation costs, you would be looking in a similar region to what it'd be for a Chlorine dosing system (I'm using a swimming pool installation as a comparison here). However, without the storage and monitoring factors to consider, the UV system has a clear advantage. 

 

How do UV water filters work?

UV units are manufactured to work within a pre-determined set of parameters. So a certain water filter would be made to treat a certain flowrate of a set quality of water. That's why you'll find different ranges of UV system, because you can't treat effluent discharge water the same way as you would drinking water.

The UV lamps that are used in the filters last for either 6 months, 1 year or 2 years and as long as they're turned on and working, the system will be doing it's job.

With all the water supply having to pass through the inline system, regardless of design style, it's very easy to plot the average dosage applied within the operating parameters using computer modelling methods.

 

Do UV water filters remove Chlorine?

They can yes, but only at very high dosages (breaking Chlorine down needs a dose of around 600mJ, so 20x higher than average). What UV will do as standard at around 50mJ is break down combined Chlorine and release it as free Chlorine. In swimming pools this has the effect of keeping Chlorine use down to around a third which has a knock on effect of reducing the top up water needed. Depending on the region your pool is in, this often has a significant impact on refill and waste costs.

 

Are water treatment systems worth it?

Depending on the issue you need a water treatment system for, there's often great value in certain types of water treatment over others. Chlorine tablets for example are very cheap to use. But a Chlorine dosing system ramps that cost right up and a UV system would then be comparable cost-wise, but without the need to keep stock of and store physical Chlorine. If you want a direct comparison between two systems you're best off speaking to us here. There are so many to choose between that it'd take an age to list them all here.    

 

UV water filtration Vs Reverse Osmosis

UV filtration and RO (also called hyperfiltration) both have merits on their behalf but they are quite different. I'll list the benefits of each here:

UV systems

• Don't physically filter out anything 
• Have very little impact on water pressure
• Target organics in the supply

RO systems

• Filter out everything 
• Big impact on water pressure and access 
• High waste water

So to compare each of these quickly. The UV unit is going to leave a lot of dead bacteria in your water. Luckily, these dissolve into constituent parts that aren't noticeable or visible, they just dissolve.

When we talk about RO filtering out everything, we mean everything. This is great if you have Arsenic or Cyanide in your water supply but flow is a big issue here. RO systems come with a bladder tank on the end to hold your treated water for when you need it. Once your bladder tank is empty you're left waiting for it to refill before you can draw any more water. It can be a little like running out of hot water in the olden days. The one thing worth extra note here is that RO will dump around 4 litres for every 1 produced. They're woefully inefficient.

One of these will likely jump out as being more suitable for you. It's not that one is better or worse than the other.

 

Which is the best home water filter?

The first thing to know here is that these systems are made all over the world. North America, China and Europe are the main manufacturers with these generalisations. China produces cheaper but passable (sometimes barely) systems. European systems are high quality and expensive. American systems are kind of in the middle but with lower standard dosages used in the U.S. their systems lend to be a little lightweight until they're huge.

In general, any European or American system will give you the same result. A UV lamp is a UV lamp at the end of the day and as long as the system is correctly specified in the first place you should be fine. They'll often be around the same cost after they end up with you as well. European systems won't need the extra shipping and storage costs applied that are associated with importing from the U.S.

Chinese systems are more tricky, I've seen a couple of units that look really great but many more that either don't use the correct manufacturing parts or are poor imitations of decent systems. I would say that buying from good, reputable companies would be more useful than going for any specific brand. UV is a niche industry where it's a good idea to talk to people and check out the warranty periods and customer support services.

If in doubt, contact us here to find out what we'd recommend for you. Oh, and we use European systems with some odd bits and bobs coming from the U.S. It's very rarely that we deal with Chinese suppliers except for specific clients.

When do I need to change my UV lamp?

Most of the time, your UV unit will start making noises at you when you need to change the lamp. But you'll probably notice that the lamp is still glowing like normal when you go to change it. So what's happening in there? Much like the smell in gas, the blue glow that your UV lamp gives out is more of a safety feature than anything else. As you'll probably know, you can't see UV light. The blue glow is there to let you know that if you can see it, you need to stop what you're doing right away. 

The thing that makes a UV lamp work is a small amount of Mercury on the inside of the UV bulb. This will often be a small ball (that will roll around and make you think something's fallen off) or a painted blob on the inside of the lamp. It's the Mercury that's used up as the bulb ages, so after a year of the lamp being turned on it'll be depleted enough so it'll drop under the recommended output that you need to kill all the bugs and bacteria in your supply. It's still powerful enough to damage your eyes and cause some pretty serious environmental issues for another 6 months after that, but it'll glow blue for years and years if you just leave it.

So do you need to change your lamp if it's still glowing? Yes you do, and probably within a month of it's expiry date. It's probably not as urgent as your squealing alarm is making you think though. 

UV and Covid treatment 

Different strains of Covid have had their effectiveness against UV tested for a number of years now, and to great effect. Traditionally UV disinfection is shown to be very effective in treating against airborne Covid. With the introduction of Covid19 we've been offering a safeguarding dosage by using the strain most closely linked to it (that we have existing information on) and including a 10% buffer for good measure. With that being the case, we feel that we can offer an option that we're comfortable will cover the requirements and do the job as intended.

Several things to note here. With UV being a physical treatment process, it relies on air circulation moving any contaminated air through the disinfection system. If someone coughs in your face, there isn't any residual effect that will protect you after the case. In places like supermarkets, moving air around at the rate that our equipment requires to show a positive effect is difficult. It will often need supporting equipment to be as effective as possible. That means that there's an associated cost and hassle factor to consider when planning is undertaken. We also feel that government legislation will soon make this is a requirement in large enclosed spaces that are open to the public. So not just supermarkets, but hospitals and shopping centres (and any other of a host of similar places) as well.    

Our safeguarding dose hasn't been officially verified yet. So we use it only as a guide.