UVC Air Purifers

Use of UVC for Home or Office Air Purification

Although most of the posts/articles in this weblog are aimed at Aquarium and Pond use of UV Sterilization/Purification, I think some time should be spent on another application for UVC radiation, especially with the onset of Flu season (including the H1N1 flu virus; AKA “the Swine Flu”). Hospitals have been employing UVC air purification systems for years do to their effectiveness in checking the spread of air borne pathogens.
Another pathogen generally spread by air is Tuberculosis; a person with Tuberculosis (TB) of the lungs or larynx can release droplets containing Mycobacterium tuberculosis into the air by coughing, sneezing, talking, or breathing. These droplets, called droplet nuclei, can cause TB infection if inhaled by anyone who shares air with the person who has Tuberculosis.

The influenza virus is actually one of the more easily destroyed pathogens by UV Radiation with only 6600 mW/cm2 required to kill this virus. Put simply, a 9 Watt UV bulb can kill this virus with an exposure time of 5.68 seconds. (See this article for further information about mW/cm2: “UVC, Watts, Microwatts, Joules, & light penetration”).
This makes for a very simple way of destroying many harmful pathogens in the home or office with an air purifier equipped with UVC bulbs.

Here are a few other pathogens and the required amount of UVC Radiation (given in mW/cm2):


This list is far from a complete list, as it is only intended to convey what the addition of UVC to an air (or even water) purification system can do for your home or office.

Ozone Production;
Generally most new Air Purifiers use non-ozone producing UVC bulbs; in fact the State of California has banned ozone producing air purifiers.
Please reference this article: http://www.arb.ca.gov/research/indoor/ozone.htm
However I should note that many air purifier manufacturers have switched to non-ozone producing UV bulbs (the aquarium/pond UV manufacturers have used non ozone producing UV bulbs as long as I have been in the industry). So if your air purifier is on the list of potentially hazardous units, chances are it is no longer is using ozone producing UVC bulbs. If you have an older unit that may employ the ozone producing bulbs, I would suggest simply switching these bulbs out with a new non ozone producing UV Bulb.

I would add as to ozone production and some of the negative reviews of some air purifiers; these reviews are all old and based on models that used ozone producing UV Bulbs from what I have read. My thought is that these headaches some complained of were due to ozone production. Headaches cannot be caused by contained non-ozone UVC purifiers.

Types;
The two most common types are the stand alone air purifier that employs UVC radiation in a shielded are of the unit or the in-Duct UV Air purifier that fits simply into most home or office air or ventilation systems.

The Sharper Image Ionic Breeze Air Purifier (pictured at the top of this article) has been around for some and employs a common 15 watt T8 UV bulb, however this unit has mixed reviews from many.

Bio zone makes several popular models of stand alone air purifiers and in duct air purifiers (pictured to the left).
Popular models include the 1000, 2000, & 3000 Air Purifiers along with the 1500 and 2500 in duct purifiers.
Most Bio zone products employ a T5 10 Watt UV Bulb

Another popular air purifier is the CaluTech “Blue” and Mini in-duct air purifiers. These in duct purifiers are simple to install and the two most popular models employ either the 18 Watt Twin Tube UV bulb (Mini) or the 36 Watt Twin Tube UV bulb (original “Blue”).

The picture below demonstrates and air duct before and after the installation of an in-duct UV purifier as per black mold (the left side is before, the right side is after):


References:
*http://uvairpurifiers.com/
*http://www.americanairandwater.com/uv_facts/tb_uv.htm
* Study: Indoor Air Purifiers That Produce Ozone Are Unsafe
*UV Replacement Bulb Reference Guide for UVC Lamps

UV Sterilizer Questions/Myths Answered

More UV Sterilizer Questions/Myths Answered

In this post I will answer two questions (or possibly “myths”) about the use of UV Sterilizer in Aquariums and Ponds based on email and phone questions I often get.
The questions are:
• Filter placement in relation to UV Sterilizer in ponds.
• Danger of UV Sterilizers to copepods in reef aquariums.

(1) Question: Is the UV best placed after or before a filter in a pond?

This question is myth based as there are valid reasons for both applications.
However based on my own use and controlled tests using UV Sterilizers with filters before, after, or not at all, the answer of using the UV Sterilizer after the filter is the better choice.

Let me explain further; when placed before a pond filter with no pre-filtration, you do catch “clumped” algae coming from the UV Sterilizer (this is even more noteworthy when a UV is run a flow rate over 25 gph per watt to 50 gph per watt as this higher flow rate will generally not kill algae outright, rather “clump” the algae where it will be expelled from the UV Sterilizer into the pond water column, then it either falls to the bottom of the pond becoming pat of the organic mulm/detritus and/or may be picked up by the pump and filter and removed. This is a reason and the ONLY to place a filter after a UV Sterilizer in pond applications.

With previous paragraph in mind, the generally better way to utilize a filter with a UV Sterilizer is to place the filter prior to the UV Sterilizer. The reason is that turbidity in the water will lower UV Sterilizer effectiveness, sometimes (based on my tests) to levels that render the UV Sterilizer ineffective. This often results in the misinformed comment that UV Sterilizers do not work (based on emails and phone calls). Pre-filtering the water improves the function of UV Sterilizer by trapping larger particulates, thus allowing more of the UVC radiation to reach the algae that is causing green water (this also improves destruction of disease pathogens at lower flow rates in both aquariums and ponds).

The other reason for pre-filtration of pond water is I have often have had success in initial clarification of pond water with no pre-filtration, but over time (& sometimes only a few weeks), sludge will build up in the UV Sterilizer (often in recesses around the UV Bulb or quartz sleeve) rendering the UV Sterilizer/Clarifier useless. This doe not mean that pre-filtration does not prevent sludge from building, as it does not, but it most definitely slows down the accumulation of sludge, as well the time it takes to buildup sludge in your pond UV Sterilizer depends on water turbidity, algae, bio load and obviously the quality of your pre-filter.

*I should note that having both a pre-filter and a post filter (such as a DIY Bio falls or similar filter that fits into the water return prior to re-entering the pond) would be an excellent combination.

(2) Question: Will a UV Sterilizer kill off my beneficial copepod & other crustaceans colonies in my reef tank?

Although not as common a question as the previous question, it still crops up from time to time and I have much harder time understanding why otherwise quite advanced reef keeper fall for what amounts to a UV Sterilizer myth.
As well, my controlled studies admittedly did not include exact counts of copepods with different levels of UV Sterilization or none at all, it did show that copepod colonies when properly established never diminished with UV Sterilizer use in reef tanks.

There is simple explanation for this result; that is most copepods do not occupy the water column in a healthy colony. What is a healthy colony? This is a matter of opinion or experience, but from my perspective a healthy colony is “housed” in large piles of live rock crumbles where many fish such as Mandarin Gobies will seek them out. As well if you are using a Refugium and want to be certain that all of the copepods/ crustaceans that spill out into the aquarium are not killed, then be sure your UV is on its own filter/pump and not returning water to the aquarium using the same return line as the Refugium. Finally whenever you dose your aquarium with certain live products such as live planktonic algae or infusoria, you should turn off the UV sterilizer or use a timer that is tied to certain cycles or automatic dosing.

My final comment to this amounts to another aquarium keeping myth, is one that has made me laugh over the years; and that is I have had clients/customers that have stood by this myth describe or show me their filter system and I have seen (or had them described) several of these filter systems that employ micron filters (such as the Ocean Clear) that can easily trap copepods in their micron filters much more effectively than a UV Sterilizer can kill copepods (in particular adult copepods for which a UV Sterilizer would have to run well under 10 gph per watt to have any chance of destroying any “pods” that get caught in the sterilizer). As well pre-filtration which should be used in any UV Sterilizer application will trap most adult copepods from entering the Sterilizer.
What makes me laugh here is that these same aquarists often had healthy copepod colonies with the use of these Micron Filters (which by the way I am not against the use of, in fact I think are excellent compliments to other aquarium filters, live rock, and healthy deep sand beds). I would explain to them that if these filters did not destroy their “pod” colonies, a UV Sterilize would not either.

Please see this article for more about UV Sterilization and how it works:
UV Sterilization

UVC irradiation and immune response

UVC irradiation and immune response
This includes human research into BioPhotonic Therapy and UVBI Therapy

This article/post is meant to expand on my previous article “Fish Immune System and UV Sterilization”), this time utilizing information about UVC irradiation as per human studies and its affect on disease treatment and over all health.
While the application to fish in aquariums/ponds is somewhat “apples to oranges” in comparison at this point in time, the implications are certainly far reaching as to the affect on Aquatic Redox and fish health.

Since most in depth research is found in human studies to do to the costs involved vs. the unfortunately common anecdotal comments made about UV Sterilization in the aquarium hobby that are years behind real research, this is where one needs to go to find good and cutting edge research. In fact I just recently came across this gem of a post of anecdotal bad information from an otherwise good aquatic article: “For me, a UV filter is just a ‘feel good’ device and leads hobbyists into a false sense of security” It is too bad that so many aquarium keepers simply refuse to do their homework, but this is likely to continue considering how lazy many persons can be at times (otherwise how can you explain the popularity of such terrible sites for aquatic information such as Yahoo Answers among many others, or directories such as DMOZ with its outdated directories).

The concept of BioPhotonic Therapy and UVBI Therapy was brought to my attention in an email and phone call by a researcher (Dr. Mamoon Kundi) who found me via my UV and Redox research articles.
One concept is clear and that is that the use of UVC lamps can affect both the oxidizing and reducing side of the Redox Balance equation that is so important for life.

Studies in UV Irradiation

In these studies, blood is irradiated (via different methods), often with very pronounced results. William Campbell Douglass, MD, who treats his patients using only alternatives and has written several books on these subjects, wrote a book called Into the Light, where he recommends Photoluminescence Therapy for the following conditions:
• Immune deficiency problems
• Viral Infections (hepatitis, respiratory, etc.)
• Pneumonia
• Non-healing wounds and wound infections
• Emphysema
• Inflammatory Processes: fibrositis (inflammation of, mainly, the muscle sheath), bursitis, iritis (inflammation of the iris), pancreatitis, etc
• Autoimmune diseases: rheumatoid arthritis, AIDS, etc.
• Osteomyelitis (bacterial infection of the bone marrow)
• Septicemia (virulent infection of the blood)
• Cancer (experimental at present)
• Peripheral vascular disease
• Most vascular disease
• Thrombophlebitis (inflammation of a blood vessel that results in blood clots)


Implications of this research as per aquariums/ponds
While we as aquarium and pond keepers are not too likely to utilize these UV blood irradiation therapies on our fish, this still has implications as to how a UV Sterilizer can be an important part of ANY aquarium keeper’s (or pond keeper) filtration system in that this latest research backs up many of my own tests and research going back to the early 1990s. The implications of the affect of the UV irradiation on how it may not necessarily outright kill pathogenic microbes found in the water column, however it certainly allows for an improved fish immune system response to pathogens, which is one of my earlier findings as well (although I did not know the whys of my test results back then). The affect of UVC irradiation also has a positive affect on Aquarium Redox Balance which is also important for aquatic health.

The bottom line is this is just one more piece of evidence that a correctly installed UV Sterilizer should be part of every serious aquarist filtration system, especially those who keep expensive, rare, or delicate fish.

Please read or at least glance over these referenced articles (more to come too):

*http://www.bio-photonictherapy.info/Home_Page.html
*http://www.oxygenhealingtherapies.com/uvb_therapy.html
*http://www.healing.org/only-7.html

As well as my UV Sterilization Article

UVC, Watts, Microwatts

UVC, Watts, Microwatts, Joules, & light penetration

This article/post is intended to give some basic understanding between the relationship of watts, microwatts, joules of UVC energy and how this translates to UV Sterilizer effectiveness.

Please keep in mind that the diagram in this article is based on air penetration, so some extrapolation is necessary for use in water applications (which is the primary intention of this article, although the principles apply to UVC air sterilization devices as well)

What is a Watt/Microwatt?

One Joule of energy = 1,000 milliWatt seconds = 1,000,000 microWatt seconds
One joule is the amount of energy required to perform the following actions:

• The work done by a force of one newton traveling through a distance of one meter (a newton is the unit of force equal to the amount of force required to accelerate a mass of one kilogram at a rate of one meter per second per second);
• The work required to move an electric charge of one coulomb (the amount of electric charge transported by a current of 1 ampere in 1 second) through an electrical potential difference of one volt; or one coulomb volt, with the symbol C•V;
• The work done to produce power of one watt continuously for one second; or one watt second (compare kilowatt hour), with the symbol W•s. Thus a kilowatt hour is 3,600,000 joules or 3.6 megajoules;
• The kinetic energy of a 2 kg mass moving at a velocity of 1 m/s. The energy is linear in the mass but quadratic in the velocity, being given by E = ½mv²;
we measure UV-C intensity in Micro-Watts that strike one square centimeter of surface area.

UVC Penetration:
(From UV Sterilization; how it works for aquariums, ponds, & more)

The emission or light intensity of a UVC germicidal light bulb is usually expressed in a term called "microwatts per square centimeter" (Mw/cm2). The maximum intensity provided by a single UVC Bulb is at its surface. So, if we calculate the surface area of the UVC lamp and only use that area which effectively emits UVC light rays, the effective area of UVC transmission will be established. Basic mathematics will show that the surface area of a cylindrical tube is ‘pie’ D L.

Next extrapolate this effective area of UVC transmission as having a screen with squares 1 centimeter in size. Each of these cm2 areas now, for measurement purposes, emits a UVC lamp intensity measured in microwatts, in other words; the term microwatts/cm2. UVC light intensity decreasingly varies as the distance from the UVC light increases.

Put more simply (a non scientific analogy); The amount of wattage will also increase penetration, as a higher watt UVC bulb will generally have more Mw/cm2. In my own experiments I have used 15 watt and 25 watt UVC bulbs in exactly the same unit (both were 18”), if wattage were only considered there would be a 60% increase in effectiveness, however I only observed a about a 25% increase. When I used a 30 Watt UVC bulb in a unit with over twice the exposure as the 15 Watt, the kill rate more than doubled. From my experience, if you increase wattage (and Mw/cm2) you need to also increase the volume of water to maximize the higher watt bulb.
Experiments can also be safely conducted with standard household light bulbs to correlate penetration. For this start with a 7 watt clear bulb (such as a Christmas bulb) and place varying thicknesses of paper/ cardboard in front of the bulb and measure when penetration stops. Continue this with higher and higher wattage bulbs.

The Diagram to the left can give a rough comparison of distance as per UVC energy as expressed by MW/cm2 in Air transmission.
The dose applied by an UV-C lamp installation is a function of the lamp output, the intensity factor, and time. As an equation; Intensity x Exposure time= microwatt seconds/cm2.
As an example, a 9 watt UVC lamp at one inch from the lamp is found by this formula:
9 x 127 = 1143 mW/cm2.
Since many bacteria such as Vibrio require a UVC exposure of 6500 mW/cm2 or more, this means an exposure time of 5.68 seconds is required to kill this pathogen


Now let me point out that even though I have published this diagram, please use this as a rough guide only, as I have found inaccuracies in it. To be more blunt; I have found the distance, wattage, and flow rate to be the MOST IMPORTANT factors in determining exposure/effectiveness. This diagram is STATIC and does NOT take into consideration the dynamics of UVC radiation penetration for which I have yet to find a good formula to demonstrate this (even in University studies).
What is often missing in any equations I have seen is the dynamics of water flow geometry, actual water flow, and wattage. The bottom line is to use this table and others you might find elsewhere with “a grain of salt” noting that these are static and even then are flawed when true output via wattage is taken into consideration.

Further Reading, references:

* UV Sterilization; how it works for aquariums, ponds, & more

*http://www.hygienitech.com/Hygienitech%20UV-C%20Light%20Primer.pdf

*http://www.solartanic.com/index_022.htm

Aquarium UV Sterilizer Ideas

Aquarium UV Sterilizer Ideas; Part Two

In part one about 18 months ago I noted using intake and return adapters as another way to connect UV Sterilizers to aquariums, especially smaller aquariums where the use of more traditional set ups such as canister filter or sumps is not possible.
In this article I will expand on this idea and as well note some problems with many sump set ups and with the growing popularity of internal UV Sterilizers, which although they make work, they are prone to leak problems that usually result in a short lifespan.

First I will start with the use of power heads, pumps, or Internal Filters (which is my first choice do to pre filtration of water allowing for a more effective UV Sterilizer).

Here is a basic picture for plumbing a compact UV Sterilizer using an Internal Filter or Power Head. The lines and can be much more neatly placed than the diagram (this is just for emphasis). This demonstration is shown on the front of the tank for easier viewing, obviously this would be placed on the back of an aquarium.
You may also place your power head/ internal filter on its side for an easier tubing application.
The picture can be enlarged by clicking on it too!

The advantage of this set up is it allows a small (or larger aquarium) that may only have a HOB filter such as a Whisper to also have a UV Sterilizer PLUS more filtration and filter redundancy.
In all bluntness this type of set up is not all that expensive when you consider the costs of fish and medications or simply piece of mind that a UV Sterilizer can provide in improving water quality (such as Redox) and lower water borne disease incidence. This is not to say that a UV Sterilizer will solve all your problems, but they are often a major piece of the good water parameter puzzle and in my experience should be included in most aquarium set ups if at all possible. Please see this article for more why: UV Sterilization

Here is a picture of an inexpensive set up that starts at $83.99 and is ready to go for an aquarium as small as a 10 gallon aquarium (there are set ups such as the 9 watt that would easily work for a 100 gallon aquarium)
Please follow this link for more information about these kits: Terminator UV Sterilizers/ Filter Kits
Please click pictures to enlarge

INTERNAL UV STERILIZERS

With the above kit or similar in mind, please be careful of the relatively new Internal UV Sterilizers sold under a couple of brand names (same design) BUT rejected by several wholesalers and retailers due to the fact that they tend to leak internally damaging, destroying the electrical components of the Unit often resulting in complete failure in under a year. I personally rejected these units after Kokaho Aquarium and other users of these Internal UV Sterilizers found total failure of most or all of them within a year or often much sooner.
What is even worse is that a manufacturer of the most popular of these internal UVs had someone spam my YouTube video demonstration of how to install a custom UV on an aquarium using Internal Filters and I commented on their clear attempt to push this product that I in good conscience could not recommend (in fact I noted in my comment that it was an awesome idea, which it is, but failed in practicality). They had the audacity to call ME unprofessional implying that I had gone to their Video when in fact that were trying to peddle their product via a comment on my video (or for clarification someone who used one of them). I think I have a right to comment on my own video!!!
They also ended up with name calling when they could not change my mind stating that "I needed help".
Honestly in my opinion this is an act of desperation by a company that may have a good concept, but is failing to sell many due to the fact that many in this industry but for a few less than honest retailers refuse to stock these Internal UV Sterilizers (or "algae killing machines").
What is also sad, is that many have criticized me for some of the unique products I do sell (such as the Wonder Shell, Aquarium Cleaning Machine), yet I only sell/use in my service items that I and others in professionally aquarium maintenance use. In the case of the JBJ and other internal UV Sterilizers I would have loved for these to work, as I think this is a good idea, but I cannot honestly sell something that I know has flaws that will lead to product failure somewhere down the road. Basically I am in a can’t win situation with some people; damned if I recommend or damned if I don’t (as in the case of these junky Internal UV Sterilizers)!

SUMP USE of UV STERILIZERS

A popular use of UV Sterilizers is in the sumps of high flow sump systems of large aquariums (especially marine), unfortunately the majority that I have seen when called out on service calls were installed improperly often resulting in the owner of the system to pronounce the UV Sterilizer a "failure" when in actuality the flow rate was way to fast for the UV Sterilizer wattage installed. As a generalization it is best to have a flow rate of under 20-30 gph per watt for a UV to be effective for bacteria, Redox, algae (slower yet for parasites) This flow rate can vary based on many factors that I will go into here (I recommend reading the link earlier in this article for more on this subject), I will only state that although you do not need to pay a fortune for a UV Sterilizer, most of the units selling for under $50 are junk and even a few name brands selling for over $100 are not delivering what you pay for.


UV Sterilizer Diverter Valves are the answer to most high flow pump problems; For use with ponds, sumps, or any high flow water application where the flow rate exceeds the recommended GPH per watt.
See this site for more: UV Sterilizer Diverter Valves

Bio Cube, UV Sterilizers

UV Sterilizers and Bio Cube Aquariums or Internal Wet/Dry Bio Filters

The Bio Cube Aquarium is a popular style of aquarium nowadays, although I have to laugh a little here as these are highly touted as a new way to keep small marine reef aquariums or planted freshwater aquariums while in reality the basic built- wet/dry filter system is nothing new to the hobby and in fact there is a new Internal Wet/Dry Bio Filter (made by the same manufacturer in China) that is less than half the cost of many Bio Cube Aquariums WITH the cost of an aquarium.
The ReSun BF 100 and 200 are the exact same filter/pump and can be used in (for example) a 40 gallon aquarium to turn it into a Bio Cube style aquarium (the addition of good lighting such as CFL/SHO, T2, or VHO is also necessary for a "higher end" or advanced aquarium). With a ReSun BF200 and your own aquarium set up the cost is often lower than many of the larger bio cube aquariums.

Anyway, the other point of this article/post is to point out that whether you use a Bio Cube Aquarium or a ReSun BF Wet/Dry Bio Filter, both of these filters systems lend themselves nicely (& easily) to a simple UC Sterilizer set up unlike say a HOB ("Hang on the back", Aquarium Power Filter) filter set up..
This is an advantage of a Bio Cube/BF 100 or 200 is that you can add a UV Sterilizer to not only lower the incidence of diseases, but just as importantly (or maybe more importantly) improve Aquarium Redox and improve fish disease resistance.

This is easily achieved by simply purchasing additional 1/2 to 5/8 inch ID tubing and running this tubing out of the aquarium to a UV Sterilizer (a 5 watt Terminator is pictured in the diagrams) and then inserting the return tubing back into the return slot on your BF 100/200 or Bio Cube Aquarium.

Please click on pictures below for a better view
This picture shows a 5 Watt Terminator UV Sterilizer connected to a 14 gallon Bio Cube Aquarium.
You can see how the tubing simply comes and out of the aquarium slots in the back of the aquarium (the slots can also be enlarged with a keyhole saw) and that the UV Sterilizer hangs easily on the back. My suggestion for most Bio Cube aquariums is a 5, 7, or 9 Watt UV Sterilizer.

This picture shows the simple mounting of a ReSun BF 200 with a Terminator 5 Watt UV Sterilizer. As with the Bio Cube application the way you add tubing is quite straight forward and as well the 5, 7, and 9 Watt UVs would also be my suggestion.

Pond UV Tips

Pond UV Clarifier Tips

* UV Clarifier/ Filter placement
A UV Sterilizer/Clarifier works best when the UV is place AFTER the filter. I know this contradicts some information I have read and this information is not necessarily wrong either, so let me explain further; By placing your Clarifier after the filter, you will remove debris that will otherwise make penetration of UVC light difficult, further more in my experience this will greatly reduce the amount of sludge buildup inside your Sterilizer/Clarifier, I will also note that the gimmicky wipers do not help much with problem. The reason some pond keepers recommend placing the filter after the UV Sterilizer is to trap algae that often clumps after passing through your clarifier, so as I noted this suggestion is not without merit. However in practical experience (along with knowledge of how uvc works), I have found that in an either or situation, the first suggestion of placing the filter first works best, this said, a pond keeper can always employ both methods for even better results, although even here I find this to make no discernable difference as to clarity, only to the amount of detritus/mulm buildup in the pond (of which controlling this via whatever means possible is certainly useful to good pond hygiene, although pond vacuums can be a useful tool here as well).

*Filters
This really goes without saying, but I will state the obvious (at least in my opinion, so please do not be insulted by my stating this point this way), USE ONE OR MORE pond filters.
Often I have had persons tell me that they bought a UV Clarifier only to realize that the new pond keeper figured the UV Sterilizer would take care of the Green Pond all by itself, which it will not. I strongly suggest a Veggie Filter in addition to a more traditional Pond Filter such as the Clear Stream Pressurized Filter, for further information about this subject, please read this article: “Aquarium and Pond Answers; Veggie Filters”.

Flow Rate
Maintain a proper flow rate to your UV Clarifier/Sterilizer either by using a slower pump or splitting the flow from your high GPH pump so as to send water to your UV at a slower rate. This is a common problem in poor UV Sterilizer installation, but easy to solve. This flow rate should be around 20-40 gph per watt, please see my Full UV Sterilization article for more about this subject: “UV Sterilization; how it works”

Please click on the picture above for a larger view at my full pond information article about how to properly connect a UV Sterilizer so as to achieve the correct flow rate

Do not waste time or money on gimmicks
I will not waste space addressing this other than stating gimmicks such as wipers or “twists” do little to improve UV Sterilization, other than lightening up your wallet.
Please read this Aquarium/Pond UV Blog Post for more about this subject: “UV Sterilizer Truths”

Maintenance
Clean your UV Sterilizer unit with each UV bulb change, which for a pond should be every season or every six months in warmer climates such as Southern California, Florida, Texas, etc. Make sure models with a quartz sleeve get the quartz sleeve cleaned as well, especially of hard water deposits (which wipers do little for).
For low price, first quality UV replacement bulbs follow either of these links (depending on your bulb type):
Standard UV Replacment Bulbs For T-5 & T-8 UV Replacement bulbs, 8 thru 50 watt; to fit Laguna, Emperor, Aqua, Aquanetics, Custom 15, Fishmate Compact, Hawaiian Marine Angstrom 2537® UV, Savio, Current USA Gamma and more.


Compact UV Replacement bulbs For (PLS, PLL, with G11 & G23 bases to fit 95% of UV Clarifiers/Sterilizers calling for this type of UVC bulb, please click the picture on the left.