High Output UVC Emission from a UV Bulb/Lamp; Aquarium or Pond

 

Last Updated: 3/9/2020

OVERVIEW;
Actual UVC output from your Aquarium/Pond UV Bulb/Lamp

A great point was brought up in one of our blogs specify geared to sterilizers and UV bulbs.
All the time, we hear about the wattage a bulb of any kind uses.
A standard light we use in our homes are 60 watt bulbs.
In water sterilizers, the bulb might be a 30 watt bulb.

The point made and the question now being; does a 30 watt UV-C bulb emit 30 watts of useful sterilizing watts?
And, the answer is No.
The UV-C wattage emitted is not the same wattage of a lamp.

Wattage of a bulb can be misleading. Watts used in a bulb is the power consumption of a bulb.
A 60 watt bulb used 60 watts of power. The actual output of a bulb is directly related to the wattage.
The higher the watts used, the great the power consumption.
But what is noteworthy, is that the wattage though does not actually tell us how much useful output the bulb has, or how efficient it is.
The efficiency of the bulb is the actual output of the bulb.

This efficiency is what becomes important as we look for a replacement for our UV Sterilizer/Clarifier or even a new UV Sterilizer as most of what is sold via the Internet or discounter brick & mortar stores are LOW OUTPUT medium pressure UV bulbs/lamps with as little as 25% of the UVC of the vastly better low pressure high output UV lamps sold but by a handful of high end sellers.
So please read on and beware if the price seems too good.

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Specify speaking about UV-C bulbs, they have a light energy spike at a certain wavelength of light (254nm). This light energy is what sterilizes.
With any UV-C bulb, there will be an energy spike at this lighting level as well use some of it lighting energy on other parts of the lighting spectrum.

The light emitted at the UV-C namometer of light is the useful energy or wattage used from the bulb. The other energy emitted on the lighting spectrum that is not UV-C is essentially wasted energy.
Therefore the wattage of the lamp is not the same wattage being emitted of UV-C.
A 30 watt UV bulb does not emit 30 watts of UV-C.

Take a look at this picture which shows the energy spike of a UV bulb. At this spike, light energy has sterilizing abilities.

In a premium low pressure true UV bulb, the actual UV-C emission of the bulb is about 35%. If you have a 30 watt UV bulb, it will emit 10.5 watts of germicidal UV-C.
Nail curing UV Bulbs, are commonly sold on Amazon & eBay for aquarium pond use at a lower cost (generally for retails prices of $5 to $15).
These are usually medium pressure UV bulb with a low 7-10% output of useful UV-C irradiation. These lamps have a wholesale cost of only a few $ for the smallest ones.
What buyers should also be aware of is how many hours the lamp/bulb is rated to last as true HO low pressure UV lamps burn themselves up quickly with only 4000 hours at peak performance. So if the lamp advertises 8000-10,000 hours--- AVOID IT!

The fact remains, that a true High Output "low pressure mercury" UV lamp/bulb has a distributor cost of at least $10 for even the smallest/cheapest of lamps, so if it is selling for this cost you know you are NOT get what you need to best run your UV Sterilizer or even Clarifier

As well the Halogen UV bulbs sold in some mini UV Sterilizers also have little of the peak UVC irradiation, more in the UVB range (these too are sold at discounters such as Amazon, not quality professional UV Sterilizer sellers). A good example of a UV Clarifier sold with these UV lamps is the Cobalt Aquatics Micro-UV which besides using the lower output Halogen UV lamp/bulb, it has very poor dwell time.

Both of these types of these low cost UV bulbs are marginal for clarification at best, certainly NOT level one or higher UV Sterilization unless used at very high wattages per water flow!! When combined with the lower dwell time that most of these Sterilizers that utilize these medium pressure lamps have (generally compact UVs), you are looking 1/4 the killing/sterilization/clarification power!!
An example would be comparing a TMC Vecton 15 Watt to a Jebaeo 55 watt that is commonly supplied with medium pressure UV lamps/bulbs (15 x 4 = 60).

As an example, if you have a 9 Watt UV Sterilizer (such as the Turbo Twist), and when the bulb is due for replacement you utilize one of the low cost medium pressure UV Bulbs, you will be getting 1/4 to 1/3 the output of a premium low pressure bulb. So if you have a flow rate of 200 gallons per hour on your say 50 gallon aquarium as would be a flow rate for low pressure UV Bulb, then switch to the low cost medium pressure UV Bulb, you would need a flow rate of 80 gph just to maintain Level One UV Sterilization.
The bottom line is to not be tempted by the low prices of the nail curing medium pressure UV Bulbs that many retailers either unknowingly or knowingly incorrectly market for pond or aquarium UV Sterilizer use!

Please Reference:
UV Sterilization; Basic Factors

Recommended Professional Source for Premium Low Pressure UV Bulbs:
*American Aquarium PREMIUM Low Pressure UV Bulbs; Compact Style
*American Aquarium PREMIUM Low Pressure UV Bulbs; Straight Tube Style (for Aqua Ultraviolet, TMC, more)

Normally, the actual emission of a UV bulb is something you will not need to worry about, but what you do what to make sure is you are getting a large enough sterilizer for the water quantity you are looking to sterilization.
Company’s that know what they are talking about will publish this information or keep it in mind, when giving recommendation.
If you are not sure, make sure to look for what kind of bulb/lamp the sterilizer has and how much UV-C you are actually getting.

UV-C Air Purifers, Surface Disinfection, Ozone

 

Use of UVC for Home or Office Air Purification & Surface Sterilization as well reasons Ozone producing Purifiers are not recommended.

Sections:

• Overview
• UV-C Irradiation Pathogen Table
• Ozone Production
• Home/Business Purifier Types

Updated 3/5/15

Overview

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:
http://www.uvsterilizerreview.com/2009/03/uvc-watts-microwatts.html.



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 Iradiation (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 (such as older Bio-Zone, King Air, Eco-Quest & many others) 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.

Please also reference this article (below) for more information as to why you should not purchase an Ozone producing purifier or replace your UV-C Lamp with an ozone producing lamp:
“Ozone Purifiers Research References”

Sadly many replacement bulb sellers or even purifier manufacturers still sell ozone producing UV-C Lamps, even many consumers strangely demand these UV-C Ozone producing bulbs (to me this is like demanding the sale of carbon monoxide suicide machines for ones home?).
In fact here is a quote from the website of a seller of the BioZone Air Purifer:
"Please Note: This air cleaner does not meet California requirements and cannot be shipped to California.".
If this does not speak volumes, I do not know what does!

Types;

The two most common types are the stand alone air purifier that employs UVC radiation in a shielded area 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 time, and employs a common 15 watt T8 UV bulb, however this unit has mixed reviews from many.
Straight tube Sharper Image 15 Watt UV Bulbs

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 three most popular models employ either the 18 Watt Twin Tube UV bulb (Mini), the 36 Watt Twin Tube UV bulb (original “Blue”), or the 55 Watt Twin Tube UV bulb (Blueray Super Output UV Air Purifier).




UV Bulb Replacements:
http://www.americanaquariumproducts.com/UVCReplacementLamp.html


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):


Another device growing in popularity for home (& restaurant too) is the "Pocket Purifier"

The Purely Pocket Purifier has a built-in UVC light bulb (lamp) that when turned on and exposed to surface areas or items needing to be disinfected/purified, will destroy the germs and bacteria killing their DNA, and preventing them from reproducing and growing.
Purchase a Pocket Purifier



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

UVC, Watts, Microwatts

 

Revised: 1/2/18

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)
UVC Air Sterilization Devices

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.
Reference: What is a coulomb?

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UVC Penetration;
A quote from an advanced sterilization article:
UV Sterilization; How a UV Sterilizer Works

"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 UV-C 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 UV-C bulb will generally have more Mw/cm2."
See this product link for high output Straight Tube UV Bulbs:
Premium HO Straight Tube UV Lamps

"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, Product Resources:

*UV Sterilization; How it works for Aquariums, Ponds, & more

*Harmful Pathogens: The Threat, mJ/cm2

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


UV Bulb; Replacement Lamps
The very best UV Replacement Lamps/Bulbs at competitive prices!

Fish Immune Health and UV Sterilizers

 

Updated 3-10-19

Fish Immune System (Including Anti-inflammatory), Redox, Oxidation, and UV Sterilization

I have seen many comments posted in various places on the internet claiming that running a UV Sterilizer 24/7 will weaken the immune system in fish in part by creating a sterile environment.
I have tried to find more information as to how this myth got its start and the best I can come up with is that many are equating UVC radiation (emitted in UV Sterilizers) to Ozone produced by Ozone Generators.

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First even though I have not found an Ozone Generator as effective as most UV Sterilizers for disease control (& Redox), even then when properly used the Ozone is not added to the aquarium.
However more importantly is that a UV Sterilizer keeps ALL UVC irradiation inside the unit and this reaction actually breaks apart free radicals and other oxidizers such as Ozone (similar to the reaction of Ozone and UV light energy in the upper atmosphere of Earth).

What is most important to note is that a properly installed UV Sterilizer will IMPROVE a fish’ immune system by creating a better Reducing Redox environment in the aquarium after water has passed through the sterilizer (providing it is a reasonably good unit such as the TMC Vecton/ Advantage UV Sterilizer, the AAP/SunSun Quality Compacts or other higher efficiency, UV Sterilizers.

See these product resource links:
*AAP/TMC Premium High Dwell Time UV Sterilizers for Aquarium & Ponds(Category A)
*AAP Compact UV Sterilizers/Clarifier (Category B)
*TMC Next Generation Ozone Generator from AAP

Here is a quote from "Aquarium Redox Potential":
"A proper Redox Potential improves the health of humans AND fish. A Redox Potential in the +125 to -200 mV range in human studies has been shown to have the same affect as anti-oxidant preparations such Vitamin C".
As well, a Category A or B UV Sterilizer improves Redox Balance via COSTANT removal of oxidizers in the water column thus DIRECTLT lowering oxidative stress in fish.

This picture of a controlled test where by an oxidizer (Potassium Permanganate) is added to the water demonstrates this ability. The control tank retains the color of the Potassium Permanganate much longer than the tank with just Category B UV Sterilization ('Category A' Sterilization will clear it even quicker, although few aquarium/pond UVs are 'Category A' any more with the AAP Vecton/Advantage one of only a couple of brands):

In medical studies the enhanced oxidizing environment can facilitate the binding of pathogens or antigens to effector cells (a type of lymphocyte that are actively engaged in secreting antibodies) leading to a hyper-responsive innate immune system.
Previous work has shown that an oxidizing environment leads to enhanced release of super-oxide and nitric oxide, activation and translocation of nuclear transcription factor and enhanced production of cytokines (proteins and peptides that are signaling compounds produced by animal cells to communicate with one another). The creation of a markedly reduced environment by addition of antioxidants blunts all of the above primary responses of the innate immune system."

In studies using human blood therapy, the use of UVC to irradiate blood, these are just a few of the findings:
*Improved circulation and oxygenation of tissues
*Anti-inflammatory effects
*Stimulation of the Immune System
*Increased Tolerance of the body to Chemotherapy and Radiation
*Cardiovascular protection
*Powerful Anti-Infection Properties
See this article for more: Oxygen Healing Therapies with UVC

It should also be noted that a True UV Sterilizer cannot create a sterile environment as it cannot reach all aspects of the aquarium such as gravel, filter media, and the fish internally!

It is unfortunate that these false statements are still widely circulated, I recommend reading this article about UV Sterilization for more:
Ultraviolet Sterilization in Aquariums and Ponds

Or this article about Aquarium Redox:
Aquarium Redox Potential

Or even this article about Aquarium Calcium, GH, KH, pH (as this is also an important aspect as well to a healthy fish immune system):
AQUARIUM CHEMISTRY

Finally, if you have a properly set-up aquarium or pond UV Sterilizer, it is important that you change your UV-C Bulb once per six months for most aquarium applications and once per year for most pond application (six months in warm year round ponds).
See this High output UVC bulb product resource link: PREMIUM High Output UV Lamps/Bulbs for Aquarium/Pond

How UV Lamps, Bulbs Work; Low/Medium Pressure, Coatings

 

Updated 1/2/19

UV (UVC) Lamps (Bulbs) used in Aquariums and Ponds and how they work.

Recommended further reading:
Actual UV-C Emission from a UV Bulb; Aquarium or Pond

This post is primarily dealing with UV bulbs(or lamps), that emit UVC radiation.
These UV lamps to be referenced here are used in the Aquarium/Pond Industry. I will discuss other UV bulb types as well, since these may someday show up in the Aquarium/pond Industry.

There are two common UVC emitting lamps types currently employed for pond or aquarium UV Sterilization: the low pressure and the medium pressure mercury lamp.
http://www.uvreplacmentbulbs.com

*The low pressure lamp emits its radiant energy between 250-260 NM which is where UV Sterilization is most effective with a UVC efficiency of about 38- 95%.
The emission peak of the Mercury electron transition within these low pressure (hot cathode) UV lamps is fixed in both energy and wavelength.

*The medium pressure lamp emits its radiant energy between 250 and 350 with many energy spikes in between (most notably around 320 which is more in the UVB range) with a UVC efficiency around 7-15%.

CAUTION: Many Medium-Pressure UV bulb/lamp manufacturers incorrectly boast that the broad UV spectral output of these lamps is more effective, which in reality is the exact opposite!!



The low pressure lamp used by most all Premium Aquarium & Pond UV Sterilizers (not always the low end UVs such as Jebo & AquaTop) is clearly the better choice based on this information.
The low pressure lamp does have one flaw which the medium pressure lamp does not suffer from and that is the low pressure lamp is affected by water (or air) temperatures and operates best between 20 C (68 F) and 40 C (104 F).
Generally this is not a major concern considering most aquarists operate their aquariums well within this range. With ponds, this is still not a major concern in that most problems, including algae occur in warmer months. This problem can be also addressed with in-line heaters to pre-warm the water.

Many UV Sterilizers come with quartz sleeves which form an air pocket between the lamps and water that in theory increases operating temperatures.
HOWEVER my own tests have shown this improvement to be nominal at best especially when compared to a well designed direct contact UV Sterilizer.
In a test with a custom 15 Watt UV Sterilizer and a 13 Watt Quartz sleeve UV Sterilizer (a well designed one at that), the increase in temperate was only 2 degrees F (I have observed up to 5 degrees depending on the units compared).
This test started at 68 F and was conducted over 15 minutes, then water was removed from the units and the temperature measured. Unfortunately the quartz sleeve is accepted as a standard that sounds great in theory, but in practicality is not a significant improvement in most applications (I would recommend them in some applications such as Lobster tanks, but even here a pre-heater would also be recommended).

Please see references for which sterilizers used in this test:
Custom 15 Watt UV Sterilizer
13 Watt Quartz sleeve UV Sterilizer

Please see this article for much more about UV Sterilization:
ULTRAVIOLET STERILIZATION (How UV sterilization works)
This article explains the benefits and myths about aquarium and pond uv sterilization


Chemical Coating in UV Lamps/Bulbs

A few companies now provide a coating that they claim extend lamp output and lamp life. I have serious doubts to these claims based on the fact the emission peak of the Mercury electron transition is fixed in both energy and wavelength and I don't think coatings can emit additional UV to any advantage. Coatings usually capture UV and convert the emission wavelength via further energy transitions to some visible part of the spectrum, perhaps with several spectral peaks depending upon the composition of the coating.

One such company, Emperor Aquatics, makes the claim that their UV Lamps feature an internal chemical coating that provides added resistance to solarization.
This company uses a picture of a new bulb/lamp with the coating and a one without. HOWEVER I in my 30 + years have never witnessed the degradation shown in this picture, and I suspect that Emperor Aquatics is using an Ozone producing UV bulb/lamp to make their point.
I stand by my experience that these coatings are simply a gimmick to charge more for their proprietary UV Bulbs

UV Lamps/Bulbs Starting

Another aspect of UV lamps that should be noted is how they function or start. Most quality UV lamps commonly used are Hot Cathode (low pressure) UV lamps. The Hot Cathode Germicidal UV Lamps are similar in their operation to the standard fluorescent lamps.
The Hot Cathode lamp operates from a ballast or transformer and requires a device such as the glow switch starter to preheat the electrodes in order to start the lamp. The electrodes, located at the ends of the lamp, are tungsten filaments coated with emission material and, under normal operation, govern the life of the lamp. In view of the fact that the life of the electrodes is shortened by frequent starts, the lamp life is rated according to the number of times the lamp is started.

Operation at low temperatures may result in excessive lamp blackening and rapid depreciation in ultraviolet 'C' output.

See Also this related post:
Long Life, Easy Start UV Bulbs

References:
*Aquarium/Pond UV Sterilizer Use
*UV Lamps & UVC Lamp Types
*UV-C Bulb Specifications; Aquarium and Pond