UV STERILIZERS ARE BECOMING MORE POPULAR AND MORE AFFORDABLE FOR AQUA HOBBYISTS.

UV Sterilizers are really starting to catch on in the Aquarium Hobbyist community. In fact, it's probably one of the most important pieces of support equipment to include in any system setup (Salt or Freshwater). Which is best? What size is needed? How do they work? How are they installed? These are several examples of some of the most frequently ask questions people ask when considering a UV Sterilizer purchase.

Let's take a minute and try to imagine what leads a person to consider the purchase of a UV Sterilizer for their fish tank. Here's a typical story about a person named Jane who's had an aquarium setup in her home for about 3 years. Jane came home from work one day with some new fish she had purchased from a reputable pet store. She was very excited to add them to her tank and knew all of the necessary precautions involved. After floating the fish in each one's respective bag for about 30 minutes, Jane set them free into the tank. They seemed fine and the other fish in the comunity got along great with the new inhabitants. After observing everyone in the tank for about two days, Jane was pleased and noted they were active and eating well.

On the third day after introducing the new fish into her aquarium, Jane noticed some of her older inhabitants began to exhibit white spots, or white areas developing on and around the pectoral fins. She didn't think too much of it after watching them for a few hours. The next morning when Jane was feeding her fish before leaving to work she noticed the white spots were spreading to all of the other fish in the aquarium. The areas were getting larger on the fish she noticed the day before (sound familiar?). She decided to stop by the pet store on her way home from work that evening to talk with the workers about her fish.

After having a 15 minute duscussion with one of the fish experts at the pet store, Jane purchased some medication to treat her aquarium. She followed the directions on the label of the medication exactly. She removed her chemical filtration to prevent it from removing the medication. She increased the tank temperature by a few degrees and maintained good aeration. As the next three days progressed her tank water began to cloud quite a bit and a couple of the smaller tank inhabitants had died. After one full week and a full treatment the spots appeared to be gone. Her tank was very cloudy and a couple more inhabitants died. Now Jane had to perform a 20% to 30% water change, replace her mechanical filtration, replace her chemical filtration, balance the ph, readjust the temperature, and start her biological filtration (bacteria colony) all over again as the medication killed off nearly all of the beneficial bacteria living in her filtration unit.

Wow! That seems like quite a bit of work. Sound familiar? This type of scenario happens over and over with so many hobbyist. The BEST defense against a situation like Jane's is a UV Sterilizer. The parasites, fungus, moulds, what ever contaminated her tank and older fish most likely was contained in the water and on the fish she brought home from the pet store. If Jane had a UV Sterilizer on hand, she could have avoided nearly all of this. If the micro-organisims were attached only to the new fish, the older fish would not have picked up the problem with a UV Sterilizer running in the tank. The beneficial bacteria colony would not have been affected at all since it remains in an area that does not come into direct contact with the UV light source.

Anything that is exposed to the UV light source is either killed or rendered harmless until it is removed via mechanical filtration. Most micro-organisms, including free floating green algae, are severely damaged and cannot reproduce after coming into contact with UV light. One very important point, and this is one huge benefit for using UV Sterilization, is that a UV Sterilizer only affects the water passing through it. Fish, plants, corals, and any other inhabitants of the aquarium or pond are completely safe and unaffected by the sterilizer. This means the ONLY impact the sterilizer has is beneficial to the environment it's processing. There's no need to remove chemical filtration. There's no need to increase aeration or modify the temperature. Any beneficial bacteria colony remains unaffected and completely oblivious to the fact that there's a UV Sterilizer in use.

WHAT THE HECK IS UV?

Let's keep this as basic as possible since this subject can quickly take a very detailed and technical direction. There are basically three categories of UV (Ultraviolet) light. Each having its own physical characteristics and how it interacts with "things" in our world. Here they are: UVA, UVB, and UVC.

The picture above shows various wavelengths, or frequencies, of light and other rays within the measurable spectrum. Radio waves being the higher frequency of the scale and Cosmic rays being on the lowest. Notice the ULTRAVIOLET range is broken down into the three regions UVA, UVB, and UVC. UV light cannot be detected by the human eye. It exists just past the lower range of visible light to most creatures on our planet. UVA and UVB are typically used to treat skin conditions. Too much of either can cause serious health problems. UVA is the range that most tanning salons use on their tanning beds. UVB is becoming more available in tanning salons and achieves essentially the same thing as UVA regarding a tan, only with less harmful effects (or so this is what they claim). UVB is commonly used in treatment facilities for skin conditions such as fungus infestations and is quite effective as a medical treatment.

UVC is considered the most effective source for germicidal sterilization. The medical community has been using UVC to sterilize tools and other things that come into contact with humans for quite some time. UVC lamps are also installed in many of the filtered water dispensing machines one can find in grocery stores. The food industry uses UVC steriliztion in many areas as well. UVC lamps have been around for quite some time and are widely used as a primary treatment or application against germs, fungus, moulds, and other pathogens.

Here are the frequency ranges for each region of UV light:

UVA = 315 - 400nm (also called Long Wave or "blacklight")
UVB = 280 - 315nm (also called Medium Wave)
UVC = less than 280nm (also called Short Wave or "germicidal")

Alright... so now we're getting a bit technical. Just remember that UVC is what makes a UV Sterilizer do what it does. When shopping around for a UV Sterilizer be sure to notice the "frequency" of light that the manufacturer or seller is advertising. It should be 250nm or close to 250nm. Most UV lamp manufacturers are right around this range.

WHICH STERILIZER IS BEST?

That's a good question. With so many available on the market, perhaps it's easier to break things down and determine what individual requirements are most suitable for the environment the UV Sterilizer will be going into. Here are some KEY points to consider:

1. Amount of water that is going to be treated (liters or gallons).
2. Where the UV Sterilizer will be placed in the aquarium setup.
3. Power rating of the UV Lamp.
4. Service requirements and servicability of UV Sterilizer unit.

Let's break each one of these KEY points down a little...

1. Amount of water that is going to be treated. Most UV sterilizers on the market that come as a complete kit (pump, lamp, lamp housing, water chamber, etc.) are rated by the total amount of water area they can effectively treat. Hmmm... this sounds too vague. The thing to remember here is AREA. How big of an area a UV Sterilizer can treat is probably the best way to rate a UV Sterilizer. It makes it so much easier for the hobbyist because they don't need to figure out flow rates of pumps, or wattage of lamps, or anything else technical. Most kits that specify a maximum treatment area are advertising the maximum amount of water contained in an area that the Sterilizer unit can effectively and continually treat without the possibility of that which it is trying to eliminate can reproduce, multiply, or grow.

Sill confused? Check this out... A UV Sterilizer that is rated to treat up to 53 gallons can elimate algae (for example) and effectively keep it from coming back for as long as the lamp life is good. Putting it into a larger area decreases its ability to eliminate and keep the algae from coming back because the algae is multiplying at a rate faster than it can be exposed. This is more of a function of the pump capacity. So why not just add a pump of higher capacity? Well, the water has to spend enough time in contact with the UV lamp so the algae receives a strong enough dose to render it useless. If the water travels too fast the algae might not be rendered harmless. Water traveling too slow is less of a problem unless the area being treated is at the maximum rated capacity. (Don't stress too much over this as their is a slight margin of error in most designs.) Pay close attention to the treatment rating. It's probably the most important consideration when deciding on a purchase.

2. Where the UV Sterilizer will be placed in the aquarium setup. Some designs require the Sterilizer unit to be "plumbed" into an existing filtration loop. These types typically do not include a pump and are configured with a treatment chamber, lamp, and power supply. These are usually placed somewhere downstream (after) the water filtration media and into the return loop. This is to avoid large particles from becoming trapped inside the exposure chamber and slowing water flow or blocking the light path.

Other designs are more "standalone" and self contained such as submersible UV Sterilizers. These types of Sterilizers are becoming more and more popular because of the convenience. I prefer these because they come complete with everything needed, pump, lamp, piping, filter sponge, power supply, and mounts. Most of these designs have been "matched" or "balanced" so the flow rates and exposure rates are optimized. This eliminates the requirement of sourcing an appropriate and compatible pump with proper flow rates verses chamber design and lamp power (Watts). Not to mention sourcing appropriate fittings, tubes, strainers, mounts, etc. Submersible designs also fit into wet/dry filters, sumps, and refugiums easily.

It's just as easy (if not easier) to drop in a submersible sterilizer as it is to treat a tank or pond with chemicals or medications. In most cases, all things considered, it's less expensive to use a UV Sterilizer than chemicals or medications. It certainly makes tank maintenance easier than if the tank was treated with chemicals or medications. There's no need for extra water changes or re-establishment of beneficial bacteria colonies and no need to re-establish or baseline water chemistry (unless there's a problem to begin with) to mention a few.

3. Power rating of the UV Lamp. This is amost always expressed in Watts. Shopping around it isn't difficult to see that there are many to choose from. 9, 11, 18, 24, and so on. Let's use cars for this analogy. Let's say one particular model comes with either a 4 cylinder or a 6 cylinder. The 4 cylinder works just fine and can get from point A to point B as effciently as the 6 cylinder. Suddenly there's a very steep hill in the road. The 4 cylinder begins to slow down half way up the hill and can't maintain a safe speed while in traffic. Soon the 4 cylinder needs to move over to the left hand lane permitting the other cars to safely pass and maintain safe traffic patterns. The 6 cylinder model has more power and didn't need to move to the left hand lane. It was capable of maintaining a safe speed with the rest of traffic and didn't fall behind. Meanwhile, the 4 cylinder finally reaches the summit but is now miles behind.

If too low of a lamp power rating is used in a sterilizer, it too can fall behind. The problem here is it can't catch up and remains behind. The algae, mould, fungus, or other pathogen is always in the lead. The Sterilizer is now behind the power curve and will remain dead last. It's almost always better to buy a higher power lamp than what is needed so the Sterilizer can remain ahead of the power curve keeping the tank clean and "sterilized".

A good guideline here is to purchase a UV Sterilizer that is rated at least 25% over the maximum capacity that is required for the area to be treated. An example would be a Sterilizer rated to treat up to 50 gallons is better suited in Aquariums of 40 gallons or smaller. This can ensure the Sterilizer will stay ahead of the "power curve".

4. Service requirements and servicability of UV Sterilizer unit. This is really a matter of convenience. Some hobbyist don't mind spending time tinkering with their aquarium or pond. In fact, many find this aspect of the hobby a favorite. Others don't want to disassemble pumbing or enjoy crawling around in the sump area. There are certain safety factors to consider as well. Especially UV lamp replacement. UVC light waves are very hazardous to most living things. Avoiding contact, especially with the eyes, is critical. Sealed lamp units are by and far the safest. These are the types that come with the UV lamp completely sealed so no UV light escapes while water is permitted to enter and exit. Most of these are discarded when the lamp wears out and a new sealed unit containing a new lamp is replaced.

SUMMARY/RECOMMENDATIONS

For the average hobbyist, the following quidelines will help ensure successful water treatment via UV Sterilization:

1. Always purchase a Sterilizer with at least 25% more treatment capacity than the size of the area that is to be treated.

2. Look to see if the unit you are interested in contains all of the necessary components and assemblies to make up a complete system.

3. Locate a reliable source for replacement lamps and lamp assemblies. Pay attention to the prices as well if this is a deciding factor in your choice of a particular model.

4. Find out how easy it is to install. Will it take more time and effort than you can afford? Will it require additional tools and equipment to complete installation?

5. Is the lamp in the UVC range? UVA and UVB are NOT considered germicidal and therefore will not effectively eliminate waterborne contaminants (i.e. Algae, mold, fungus, and other pathogens).

LAST BUT NOT LEAST... WHAT A UV STERILIZER WILL NOT DO!

1. UV sterilization will not cure infected fish of bacterial or fungal diseases. A UV can aid in the cure by killing bacterial pathogens and fungal spores in the water column, also by improvement of the Redox potential and general water quality.

2. A UV sterilizer will not kill ich trophozoites already on the fish, but UVC can again slow the spread of ich tomites in the water column.

3. A UV sterilizer will not kill beneficial bacteria such as aerobic bacteria, as this bacterium is effective when attached to a surface of high water flow such as the sponge of a sponge filter, NOT when in the water column. THIS MEANS IF IT'S FREE FLOATING IN THE TANK IT WILL BE "NEUTRALIZED". It is best to turn off a sterilizer unit when introducing bacteria to seed a new aquarium. It is best to maintain mechanical, chemical, and biological filtration when using a UV Sterilizer. The "dead" material needs to be removed.

4. UV Sterilization will not remove or destroy algae growing on tank or pond sides, rocks, decorations, ect. IF IT'S FREEFLOATING IN THE TANK IT WILL BE "NEUTRALIZED".

5. UV Sterilization will NOT make up for poor aquarium maintenance practices such as over crowding, over feeding, inadequate filtration, poor cleaning practices, improper water parameters, and more.