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UV Sterilizer Reviews; Information Articles, Ideas, Comments, and Links to even more Resources about how UVC Sterilization works in Aquariums/ Ponds

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Aquarium-Pond UV Sterilizer History


Last Updated: 3/2/2019

Aquarium-Pond UV Sterilizer History (from my professional perspective dating back to 1978)

True Aquarium UV Sterilizers as well as Clarifiers have actually changed very little in the what's important and defines a useful sterilizer (which most of the Sterilizers now sold by discounters such as Amazon, eBay, AquaTop, Chewy.com, etc, are actually just Clarifiers). This is unlike aquarium lighting and some other aspects of aquarium (& pond) keeping that have changed radically.

What has changed is how they are packaged and sold.

Decades back, most all UV Sterilizers used low pressure UVC bulbs/lamps, but now many use medium pressure and/or cold cathode UV lamps, which are much less efficient, but vastly less expensive. About the only differences were how the containment unit was designed, which affected exposure/dwell time and the use of a quartz sleeve or not.
As well, when new ideas came out, which did not work well, these were quickly retired as the industry was mostly driven by professional use and serious aquarium supply stores.
Unfortunately of late, some of these same bad designs have resurfaced, but are surviving in our "sound-bite", Internet, big box retailer, & Amazon/eBay review world where measured science/experience based results do not matter anymore.

This is quite unfortunate, as this has allowed many poor quality UVs to survive, which use medium pressure UV lamps (which provide about 1/4 the UVC of a quality low pressure lamp), poor designs such as some of the "Hang on the Back" designs, which nothing more than copies of the failed Nektonics designs from the late 70s to early 80s, as well as submersible UV that not only include the first two faults, but also do not include important pre-filtration (these are commonly sold by Amazon).
This result has further helped with the myth that a UV Sterilizer is good for nothing more than clarification when in fact this is only true of UV Clarifiers (or UV Clarifiers that are marketed as UV Sterilizers but in reality are far from a TRUE Category A capable UV Sterilizer). The truth is a TRUE category A UV Sterilizer can demonstrably do so much more from disease prevention to lowering oxidative stress in the aquarium (or pond)


So the purpose of this article is to provide some history of the aquarium/pond UV going back to about 1978, so as to help reader make better informed decisions before purchasing such an important piece of aquarium or pond equipment, which not only is well known for helping with clarity, but also with some disease prevention, as well as the lessor known help a good UV provide with Redox Balance, which in turn improves fish and other aquarium inhabitant immunity.

Some Background- I have been in the hobby since about 1967 and professionally employed since 1978. One of my expertise fields is fish disease prevention where I have carried out dozens experiments, along as made literally 1000s of observations in the 1000s of client's aquariums over the year in my care. UV Sterilization in particular became a major interest for me where I performed many experiments, and made many more observations. I also designed my own UV units to further experiment with. In addition, I also regularly attended trade shows and spoke with many experts in this field too which include Aquanetics and Aquatronics.

I will provide highlights of certain UV Sterilizers that I had considerable experience with and also represents important aspects and key developments of aquarium/pond UV Sterilizers. This is not meant to be an exhaustive list.
Also any times given are not meant to be exact, as well these are based on my time of use, not the years they were available to the general public.

  • Aquanetics UV Sterilizers:

    Aquanetics UV SterilizerCirca 1978- 1990?
    These are one of the best early UV Sterilizers I used and would also in turn recommend and sell based on results.

    These were generally an in-line UV Sterilizer that utilized 15, 25, & 30 Watt T8 style low pressure UV lamps/bulbs.
    Many of these also were straight water contact with the lamp with no quartz sleeve, although quartz sleeve models did become available too.
    The Aquanetics at the time I used these utilized reliable magnetic ballasts with starters, most of which the ballast themselves rarely went bad unless there was a leak in a seal and water got to the ballast.

    Most of these UVs lasted a decade or more, had an excellent dwell time and most importantly produced excellent results both by dozens observations and a few controlled test later in the 1980s using a bare tank with cloudy water and timing the clearing time.

    Aquanetics UV Sterilizer versus LifeguardIn fact I had an Aquanetics 15 IL UV mated to a canister filter that I used to rotate to client aquariums that did not have a running UV. However one time I had client that already had a working LifeGuard 8 watt where the tank was cloudy, so I added this Aquanetics UV and within two hours the customer called and told me the tank was crystal clear.
    This really sold me on this line of UVs which I later performed tests on as it made me realize in my early years that not all UVs were equal. Later as Aquanetics became difficult to obtain I went with the TMC line of UVs (which unfortunately of late are also becoming difficult to obtain world flooded by cheap UV Sterilizers

  • Nektonics UV Sterilizers that connected to filters:

    Circa 1978- 1981?
    When these came out, I thought that this UV was a great idea as it allowed a compact UV that utilized a "non-traditional" 5 watt "bulb shaped" UV lamp whereby water was circulated in a non regulated fashion around the lamp. This UV connected easily to lift tubes such as the excellent Nektonics Under Gravel filter (their UV filters with their patented corrugated design were vastly more efficient than other flat plate UG filters).

    Unfortunately, the design allowed for constant calcium deposits on and around the lamp. The design also did not establish a very good flow pattern and thus a reliable dwell time was not assured. The distance from the lamp to the wall of the UV sterilization chamber was also higher than the Aquanetics resulting in poor sterilization capabilities.

    So in the end where I bought over a dozen of these UV Sterilizers, I found that while they could perform some clarification (even then taking much longer than the Nektonics), these simply were not a very good UV.
    An example would be, I had several marine oodinium outbreaks with these UVs in place, but once swapped out for the Aquanetics, while I still had an occasional incidence of oodinium, it was easily cut by 75% in the dozen marine tanks I swapped out UVs for

    This is not to knock Nektonics, as at the time they were often a cutting edge manufacturer of aquarium products, especially aimed at the growing in popularity marine fish keeping hobby, these were just unfortunately a "fail" that I learned from as I worked with UV Sterilizers in the future, including in designing some custom UVs of my own.

    Sadly, this design has come back from the grave in many HOB type UV sterilizers, that often also utilize medium pressure UV bulbs/lamps (at least the Nektonics used a low pressure UV lamp). These HOB units under the name of Aqueon, Aquatop and others are commonly sold by Amazon and other mass merchandisers, and sadly promoted by some inexperienced YouTubers such as "My Aquarium Box"
    So be wary of wasting your money on these, no matter how appealing the $30-$50 price for a UV Sterilizer combined with a filter that hangs on the back of your aquarium. In reality, these nothing more than basic filter with a pretty blue light inside them!!

    Further Reading About Medium Pressure UV Bulbs:
    Actual UV-C Emission from a UV Bulb; Aquarium or Pond

  • Lifeguard Modular UV Sterilizers (Models QL-8 & QL-15:

    Lifeguard modular UV SterilizerCirca 1978- ?
    The Lifeguard modular QL Sterilizers were/are a popular UV Sterilizer, which I did not initially purchase for my clients, but inherited at 10+ from clients who purchased their aquarium equipment elsewhere then contacted me for aquarium maintenance.
    These are a solid construction UV Sterilizer.
    These LifeGuard UVs used newer T5 lamps (smaller diameter than T8), but any improved efficiencies from these lamps were lost by a poor design that had poor water/UVC contact.

    In one example, I had a new client with a new LifeGuard QL UV, which had a cloudy 55 gallon hex shaped aquarium (which clearing an aquarium is generally a basic ability of UV Sterilizers). I brought over an Aquanetics 15 Watt run by a canister filter I used for moving from aquarium to aquarium, this aquarium was clear in a matter of hours.
    In every case I changed out these UV Sterilizers, I found similar improvements, although not all this dramatic. As with Nektonics, Lifegaurd has made many excellent products over the years, however my experience was these simply were not the best UV Sterilizer design. As well, like many Lifeguard products, these were over priced in my view, and Lifeguard was never very good at supporting aquarium professionals, often under selling to mail order and later discount online sellers rather than full service sellers (both online and stores), so in the end I am not a "fan" of this company.

    Further Reading: Turbo Twist, LifeGuard UV Sterilizer Review

  • Tetra Pond UVC-5, 9, 18, & 36:

    Tetra Pond UV SterilizerCirca 1988- ?
    This well made UV has been around in some form. While designated a Pond UV, I have also used it in aquariums too with good results.

    These are what are called "Compact UV Sterilizers" and use use a different style UV lamps than the straight tube UVs. These lamps/bulbs carry designations such as PLL, PLS, G23, G7, G11.
    Tetra only uses only quality low pressure high output UVC lamps/bulbs, however Tetra also makes many of the lamps proprietary so that it can be difficult to find the lamp without paying 2-3 times what a comparable high quality low pressure UV lamps would sell for.
    Thankfully some other options for quality replacement bulbs/lamps are now available at a better cost
    Resource: Premium UVC Replacement Bulbs/Lamps; Including Tetra G-7 9 Watt and G11 18 Watt

    Another issue I have with the Tetra UV is that while these are well designed and well made, there are also comparable quality UVs in build and lamp usage such as the SunSun Terminator for much less in cost. So often a buyer will pay considerably more for their Tetra UV and not actually get a better unit.

  • Pressurized Pond Filters with Built in UV Clarifiers/Sterilizers:

    Tetra Pressurized Pond Filter with UV SterilizerCirca 1988- ?
    The pressurized pond filter which fits in line from a water pump to many water features in a pond became a very popular method of efficient pond filtration.
    Later UV Clarifiers/Sterilizers were added to these filters including the Tetra, Nursery Pro, Via Aqua, SunSun and MANY others.

    The first one I used were the Tetra Pressurized Pond filter with UV. However I immediately noted that these were not very efficient even for basic clarification (even though the filter worked well).
    Upon adding a similar sized Tetra UV Sterilizer such as a 9 Watt, the improvements were dramatic as per clarification or speed of clarification.

    Why these poor results? for one the flow rate often over 2000 gph is simply too high for a 9 watt UV or most size UV lamps used, no matter the quality. As well the design of these filters do not lend them to optimum contact/dwell time. I have found this to be true regardless of brand.

    My suggestion is to utilize a separate quality UV Sterilizer in line AFTER your filter and if your flow rate is too high, which is likely, having a diverter valve after the filter so as to slow the flow rate to a rate more effective for clarification will improve results dramatically (under 50-70 gph per watt depending upon model). Reference: UV Sterilization; Flow Rate Table

    Product Source: Upgraded Pressurized Pond Filter with UV

  • Coralife Turbo Twist Compact UV Sterilizers:

    Circa 1995- ?
    This is another Compact UV like the Tetra that also uses quality low pressure high output UVC lamps/bulbs.

    However their design, which uses what I would describe as baffles does not lend itself to optimum water contact, and my use of many confirmed this with lessor results.

    Another issue that has come up with more recent usages is with the poor quality of their ballasts. My aquarium maintenance company bought a case of these Turbo Twist UVs and over a year time span, EVERY ONE FAILED!
    While this problem may already be fixed, based on this experience and effectiveness of design as well as the higher cost, these are definitely a UV Sterilizer I would not recommend.

    Further Reading: Turbo Twist, LifeGuard UV Sterilizer Review

  • Other Compact UV Sterilizers:

    Via Aqua, SunSun Terminator UV SterilizerCirca 1990- ?
    Many other Compact UV Sterilizer/Clarifiers have come out over the years, some good like the Tetra, but at a lower price such as the Via Aqua Terminator & newer SunSun version, some of much lower quality and design, including utilizing 25% of the output medium pressure UV Bulbs/Lamps when compared to higher output (and higher cost too) low pressure UV Bulbs/Lamps.

    The first incarnation of the Terminator was an excellent well built UV Sterilizer that had a good electronic ballasts (not all are as noted in the Coralife Turbo Twist section). The retail selling price was also much lower than the Tetra and these units also did not utilize the proprietary UV replacement Bulbs that the Tetra Compact UVs did. This resulted in the Terminator being my go to economy Compact UV for which I sold and used literally 100s.

    Unfortunately around 2010, and partly due to infringement on designs of many of their products, Via Aqua changed their design to one, which while still good, was a bit less reliable and more prone to workmanship issues.
    Later Via Aqua dropped this UV too.

    Thankfully SunSun has models that follow the original Terminator design, although they are not always equipped with low pressure UV bulbs out of the factory unless requested by the distributor and/or retailer. So be wary of some low price sellers of SunSun UV Sterilizers (Compact or otherwise) that are too cheap to be true, as these likely have lower price point medium pressure UV Bulbs.
    Further Reading About Medium Pressure UV Bulbs:
    Actual UV-C Emission from a UV Bulb; Aquarium or Pond

    Recommended Resource for SunSun Compact UV Sterilizers:
    SunSun Compact UV Sterilizers with High Output UV Bulbs/Lamps

  • Aqua, Emperor, & TMC UV Sterilizers:

    Emperor UV Sterilizer Review Circa 1990- ?
    The Aqua Ultraviolet, Emperor, and TMC/AAP Vecton & Advantage UV Sterilizers were three of the high end premium models I started using in the 1990s (this does not mean these were not around earlier). When the Aquanetics became less available along with new suppliers and new clients who already had this equipment before contracting with me for their aquarium or pond care, these were the three premium UVs I had the most exposure to.

    I found that the Aqua Ultraviolet along with the often similar Emperor UV to be excellent UVs with unsurpassed efficiency based many observations and a few of my simple bare tank timed clarification tests as well.
    The Aqua Ultraviolet & Emperor UV also unfortunately came out with gimmicky features such as wipers to supposedly scrap off build-up of material on the quartz sleeve between lamp/quartz sleeve 6-12 month servicings. However, while this worked OK with organic mulm, this feature did nothing for the main problem of build-up; hard water deposits.
    Reliability was excellent, but the few times of need of manufacturer warranty customer service as well as parts availability, these UVs were not as easy to take care of.

    My other complaint is not really with the unit itself, rather how the Emperor 50 Watt Smart UV is unfortunately marketed by a popular online discount reef supply seller that shows their limited experience using UV Sterilizers.
    While most definitely a very well built UV Sterilizer, it has poor dwell time in proportion to the input wattage used due to exposure time with the T5 lamp and high water volume within the reaction chamber.

    Here is some information as to why their claims are not totally correct (please note that the Emperor Smart 50 watt uses a T5 lamp):
    "While T5 lamps are roughly 16% more efficient at converting electrical energy into light energy, this does not necessarily make the T5 the better lamp as some have stated. Given two lamps of equal length, equal UVC light output, and equal flow rates, then the dwell time will be the same, and the germicidal effectiveness will be practically indistinguishable, regardless of the number of electrical watts pumped into each one.
    As an analogy it is like saying that if my car goes 140 mph with a 200 hp engine, and 160 mph with a 300 hp engine, then a 300 hp HYBRID engine (using 16% less gas) will make my car go 180 mph (as per the logic of using a T5 over a T8 UV lamp).

    Also, if the manufacturer uses a 5/8" diameter T5 instead of a 1" diameter T8, and reduces the tube sleeve diameter by 3/8" (compared to a T8 fixture), and then reduces the reaction chamber diameter by 3/8" (to stay within 3cm of the tube sleeve); in that case, the T5 fixture will have a smaller cross section area, which will REDUCE the dwell time for any given volume flow rate."

    Reference for Quote above: UV Sterilizer Dwell Time Test

    Further Reading: UV Sterilization; What Makes a Good UV Sterilizer

    Aqua UV versus TMC UV Sterilizer
    VIDEO: Aqua Pond UV vs TMC AAP Pond UV Clarifier Sterilizer

    A comparison of the two top large pond/aquarium-system UV Sterilizers and why the AAP/TMC comes out as the best when price and dwell time is considered

    TMC Vecton UV SterilizerAAP/TMC had a similar well made offering; the Vecton for aquariums and the Advantage primarily for ponds, although I have used several for aquariums too.
    Problems were non existent other than the occasional UV arriving with a broken quartz sleeve, this now in 1000s of sales/uses.
    My only complaint is earlier models of Vectons came with a gimmicky time set feature that was really a waste of time, thankfully they did away with this in favor of a much more practical 90 degree elbow that is now included.

    The Vecton is designed to be more compact and have a lower water volume design along with slightly better UVC exposure than the Advantage. The earlier versions of the Vectons has a rather gimmicky light set that was supposed to help remind the user when to change the lamp, however the normal method of keeping a log is actually more simple. Thankfully, this silly feature was done away with and instead the UV includes a more practical 90 degree elbow.

    Overall reliability as well as performance has been unsurpassed when compared to any other UV I have used.

    Parts availability is also second to none as many UVs nowadays do not have many parts other than the UV lamps readily available. I also like that the 30 watt models and lower still use a very heavy duty magnetic ballast, as I have found that even with the best of electronic ballasts, a 5 year life is often the best you will get which is not the case with these Vecton (& Advantages).
    Even if warranty service is needed (which again I have yet to need this in 1000s of applications), the UV only need be taken to the original retailer, not sent away by the owner for repairs.

    TMC Advantage UV Sterilizer

    Everything I stated about the Vecton as per reliability and performance holds true for the Advantage as well.

    The difference is the 55 Watt Advantage model (not available in North America) & the 110 watt model utilize an electronic ballast, which is still as good and reliable as any electronic ballast I have ever used, but just not as reliable as the TMC magnetic ballasts used in the smaller Advantages and Vectons. As per ballasts, what is noteworthy is that I have never replaced a failed magnetic ballast in any TMC UV other than when it was damaged by water, not by defect.
    This said, an extremely misguided USA 2014 (& dare I say anti small business) regulation has banned the use of magnetic ballasts which are actually better for firing HO UV Sterilizers of lower wattages, so now many models of both Vecton & Advantage have been discontinued and those still made now utilize electronic ballasts.
    AAP has been able to secure the UK 220/240V model in the Vecton 200 (8 watt) which still utilizes the magnetic ballast and provide a converter for North American markets.

    Back to differences between the Vecton & Advantage; the other difference is the volume of water the Advantage can hold when compared apples to apples such as the Vecton 25 watt to the Advantage 25 watt. The Advantage holds more water which allows for the higher flow rates generally needed/desired in ponds, however the UVC exposure is lower in the Advantages for this same reason.

    Overall, while I have used equally good UV Sterilizers as in the Aqua Ultraviolet, when value, parts availability, reliability, and warranty are considered, the TMC/AAP Advantage/Vecton UVs have been my clear choice for use personally and with my clients.

    Recommended Resource for AAP/TMC Premium UV Sterilizers:
    TMC Advantage & Vecton Aquarium/Pond Premium UV Sterilizer

  • Internal/Submersible UV Sterilizers:

    Green Killing Machine UV Sterilizer ReviewCirca 2007- ?
    Internal/Submersible UV Sterilizers/Clarifiers in their current form are relatively new to the aquarium/pond hobby/industry.
    However, they have unfortunately taken the hobby by storm. Why unfortunately? Because the vast majority are only good as clarifiers, despite less than honest statement these can actually be useful for disease pathogen control and Redox balance magnetism. The other major issue is many have issues with seals and/or ballast, resulting in life spans of well under a year, which does not seem to show up in poor Amazon reviews since these UVs usually get reviewed based on initial use.

    It is noteworthy that one of the first to enter the market was the Green Killing Machine. It was quickly rejected by professional aquarium maintenance professionals due to its short life and ability to only clarify, but good marketing to discounters has allowed this product to unfortunately proliferate the market.

    One other problem with the vast majority of the submersible/internal UVs is these do not utilize pre-filtration which is very important for effective UV Sterilization. Nor do most use high output UVC low pressure UV bulbs and instead utilize 1/4 output of UVC medium pressure UV Bulbs

    The first one to finally get it right is the AAP version of SunSun CUP 9 and 13 Watt which have pre-filtration, low pressure UV Bulbs, and a correct flow rate for the watt of UV used. Even then while these are True Category B UVs, these are still an economy UV Sterilizer and being submersible will not provide as along a life as in-line models such as the Terminator.
    Unfortunately these same exact model numbers are also sold on Amazon without these important features for those who are unfamiliar with what is important for a decent UV Sterilizer.

    Further Reading:
    -UV Sterilizer Problems & Reviews; Submersible Pond, UVC Clarifier
    -Actual UV-C Emission from a UV Bulb; Aquarium or Pond
    -Common Aquarium Keeping Myths

    Recommended Resource for SunSun CUP Submersible UV Sterilizers:
    SunSun Submersible UV Sterilizers with High Output UV Bulbs/Lamps & Pre-Filters

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