UV Sterilizer

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Today, novices and advanced aquarists are achieving greater success because of two factors:
- The availability of more information about aquarium, and pond keeping -
- The development of new products and techniques through research -

The manufacturer of the AQUA Ultraviolet Sterilizer is dedicated to both of these advancements.
This information sheet is one of a series intended to better inform aquarists so that all fish and invertebrates will live longer,
healthier lives, leading to greater satisfaction and enjoyment for all concerned.

THE CLEAN, QUIET AND EFFICIENT WAY TO A HEALTHY AQUARIUM,
GARDEN POND OR PROFESSIONAL INSTALLATIONS


Maintaining fish in an aquarium or pond requires that the artificial environment be held in a stable condition, free of both organic and inorganic pollutants. The water should be well oxygenated, lighted and kept at a reasonable constant temperature level. Unfortunately, the factors contributing to the well-being of tropical fish can be disrupted, allowing the proliferation of dangerous microorganism-bacteria,parasites, protozoa, viruses and fungus.

Standard mechanical and biological filters will not eliminate an abundance of unwanted microorganisms. Ultraviolet sterilization is a proven method to control lethal organisms in fresh water and marine aquariums. The value of ultraviolet sterilisation is as safeguard against rapid increases in potentially lethal bacterial populations. The importance of this feature an amplified in aquarium system containing fish that may be weak as a result of improper feeding, handling or parasites. The water can be circulated to the AQUA-UV filter unit by a small pump or the pressure tubing of a powered filter. The water enters the sterilizer through the bottom inlet and moves upward. This prevents air to be trapped in the UV unit.
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WHAT IS ULTRAVIOLET LIGHT

Ultraviolet light is the name given to the light waves that fall between X-rays and visible light rays in the electromagnetic spectrum.
The ultraviolet (UV) light is further divided into three classifications; extreme UV (wavelength less than 2000 Angstrom), near UV (wavelength between 3000 and 4000 Angstrom) and far UV section (UV-C), which is our specific area of interest (wavelength from 2000 to 3000 Angstrom) and is classified as the germicidal region.
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SOURCE OF ULTRAVIOLET LIGHT

Ultraviolet light is produced by the sun.
However, by the time the UV light reaches the earth it has been reduced to minimal intensities by such factors as the atmospheric conditions, latitude, and time of the day.
Artifical UV light in the germicidal region is available through the use of commercially available lamps.
Germicidal lamps are similar in size and wattage to standard fluorescent lamps.
UV light (energy) is produced by a low pressure mercury lamp made from a glass formula which permits the passage of light rays of a specific wave length.
The strongest effectiveness of a germicidal lamp is approximately at a wave length of 2537 Angstrom.
The term Angstrom is a unit used to express the length of light waves (one tenth of a millimicron or one hundred-millionth of a centimeter).
UV light is invisible to the human eye, but consists of a high radiation energy level.
When microorganisms are exposed to this light, the UV energy causes a change in the chemical bonds of the DNA (deoxyribonucleid acid) molecules and, with microorganisms, this chemical alteration result in their destruction.
Fortunately, UV radiations do not affect taste, odour or produce significant chemical changes in the water, a distinct advantage for UV sterilization.
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HOW UV LIGHT (ENERGY) WORKS

When microorganisms are exposed to the UV light, the UV energy causes a change in the chemical bonds of the DNA molecules which results in their death.
The AQUA-UV Ultraviolet Sterilizer will function without altering the pH or chemical structure of the aquarium water.
Also, this unit will not adversely affect the fish or beneficial nitritying bacteria and algae settled in the filter or in the aquarium.
It should be noted that the germicidal lamps produce a fraction of light energy, including visible light, at wavelengths other than at 2537 Angstroms.
Approximately 30% of the input energy provided to a germicidal lamp is converted into usable UV light at 2537 Angstroms.
The remaining energy is divided between heat and visible light.
The AQUA-UV UV filter units are uniquely designed to permit the water to pass all around the germicidal lamp, taking advantage of the 360º degrees light source.
The UV energy generated by the germicidal lamp is transmitted through the water onto the inside surface of the filter housing, thus exposing all of the microorganisms in the water to a UV intensity equal to or greater than the intensity at the wall.
The total depth of penetration (distance beween lamp and inside surface of the filter housing) varies for each model, however, the maximum depth is approximately 2,5 cm (1") on the AN-15 and AN-25 models.
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GERMICIDAL EFFECTIVENESS IN WATER

The germicidal effectiveness or % kill of microorganisms is usually controlled by the depth of penetration by UV light through the water.
The germicidal effectiveness decreases as the distance from the lamp increases.
Therefore, the amount of UV energy available to kill microorganisms in the water is dependent upon the water to transmit UV light.
The greater the amount of energy absorbed by the water, the less there will be available to kill micro-organisms.
Factors that can influence the transmission of UV light in water include the clarity and existence of any particulate matter in the water.
Distilled water would be the best water available.
Water with a high content of particulate matter will decrease the UV transmission by absorbing the UV energy intended for the micro-organisms.
Synthetic and common salts do not interfere with the UV energy.
Two factors which can also effect the overall germicidal effectiveness in water are the lamp life and the lamp operating temperature.
Lamp Life.
The output intensity of a UV lamp is reduced as the lamp gets older.
Excessive start and stop cycles will shorten the life of the lamp.
Continuous operation will lengthen the life.
Operating temperature:
The lamp operating temperature is controlled by the medium (air or water)next to the lamp and its relative efficiency in conducting or dissipating heat to or from the lamp surface.
The best operating temperature of the lamp is approximately 40 degrees C.
Operating temperatures significantly above or below this temperature will reduce the germicidal output of the lamp.
Under most aquarium conditions, the germicidal lamp will operate at temperatures close to the optimum and little efficiency will be lost due to the temperature effect.
Reviewing the required UV intensity values to destroy microorganisms, it can be seen that most bacteria can be killed with a relatively low UV intensity while parasites require a much higher intensity.
What this means to the aquarist is that for a given AQUA-UV unit, the lower the flow rate through the unit, the higher the level of UV intensity available to destroy unwanted micro-organisms.
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AQUA-UV STERILIZERS

The AQUA-UV filter units offered in different models are sized to meet the requirements of fresh and marine water aquariums up to 9000 liters capacity.
Greater flow capacity can be achieved by connecting 2 or more units in parallel operation.
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QUESTIONS AND ANSWERS REGARDING ULTRAVIOLET STERILIZERS

Do we need an Ultraviolet Sterilizer?

Fish in an aquarium or garden pond live in only a fractional amount of water compared to their life in free nature.
Food remains, excretions, algae and other waterborne micro-organisms will create unwanted organic matters in the water.
Unfortunately, mechanical and biological filters will not prevent the proliferation of harmful bacteria.
AQUA-UV ultraviolet sterilizers have proven to be an effective method of eliminating dangerous micro-organisms like parasites and viruses, in addition to floating algae clouding the water.

What is ultraviolet light?

Ultraviolet light is the name given to the light waves that fall between X-rays and visible light rays in the electromagnetic spectrum.
Ultraviolet light is invisible to the human eye, but consists of a high radiation energy level
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What is the source of ultraviolet light?

The best known source of ultraviolet light is the sun.
It is a known fact that sunlight can prevent the spreading of infections.
It was noticed that the propagation of micro-organisms was stopped when exposed to sunlight.
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How is ultraviolet light produced?

Ultraviolet light (energy) can be produced artifi-cially by a low pressure mercury lamp made from a glass formula which permits the passage of light ray of a specific wave length.
The best effectiveness of a germicidal lamp is at a wave length of 2537 angstrom.
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How does an AQUA-UV sterilizer function to eliminate dangerous organisms?

When organisms are exposed to the UV light, the UV energy causes a change in the chemical bonds of the DNA (deoxyribonucleic acid) molecules, preventing their multiplication, which results in their elimination.
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How are the micro-organisms exposed to the ultraviolet energy?

The water can be circulated through the sterilizer by a small pump or the pressure tubing of a powered filter.
The UV lamp in the center of the unit emits a 360º germicidal energy which will reach and eliminate all bacteria, algae, viruses and parasites carried by the water.
The longer the water remains under the influence of the UV energy, the better the overall germicidal effecti-veness will be.
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Can an overdose of UV sterilization occur?

No.
The water can neither store nor carry UV energy.
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Can the sterilizer adversely affect the beneficial nitrifying bacteria and algae?

Only micro-organisms, like algae, parasites or viruses, floating in the water and exposed to the UV energy are eliminated.
Nitrifying bacteria contributing to the well-being of fish are not carried to the sterilizer, and therefore do not come in contact with the UV light and will not be destroyed.
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Should the sterilizer be kept in continuous operation at all time?

The answer is yes.
Multiple start and stop cycles will shorten the life and effectivness of the lamp.
In addition, stop cycles will again permit the multiplication of dangerous micro-organisms.
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What is the main feature of the AQUA-UV unit?

The large water volume in the canister permits a sufficient exposure time for the destruction of over 99% of all the micro-organisms.