philgmiami
Member
What exactly is UV sterilization? It's actually a very simple process for removing (referred to as filtering) unwanted free floating microscopic water borne bacteria, parasitic, fungal, viral, algae, and other unfriendly pathogens out of aquarium water by exposing it to high intensity ultra-violet (UV) light. UV light has the ability to effect the function of living cells by altering the structure of the cells nuclear material, or DNA. The end result is the organisms die off, eradicating your aquarium water of these unwanted nuisances.
Suggested wattages are 4-8 watts for 20-40 gallon aquariums, 20-25 watts for 50-100 gallons, and 40 watts for larger aquariums. Using this method of treating water is quite controversial amongst aquarists. Some consider it to be a waste of money, not all that effective, or suitable for fish-only, but unnatural for reef tanks, while others feel it does have its benefits for either type of system.
The general consensus is that an aquarist that has a well maintained and uncrowded aquarium, as well as follows good quarantine procedures when introducing new specimens to their system, a UV light filter is not necessary. For those that may be deciding on whether a UV light filter should be added or not, here are some other points to consider.
Most effective when run 24/7.
Most effective if the water is clear.
Most effective if bulb is new, or replaced regularly (at least every 6-8 months).
Most effective if the UV light penetrates less than one inch of water.
Effectiveness can be hindered if the water passes to fast past the bulb. Most effective if the exposure time of the water to the UV light is longer than one second.
The effectiveness of UV light can be hindered if there is light blockage, i.e. a salt encrusted bulb.
It can help to prevent future water borne pathogen reoccurrences, once the initial problem as been completely eradicated from the aquarium.
UV light not only kills unwanted organisms, but beneficial ones as well.
Because it can destroy beneficial microscopic organisms that some reef tank inhabitants may depend on as a food source, UV light should not be run during feeding time.
It only destroys organisms that are free floating IN the water as it passed by the UV light, i.e. it will NOT get rid of an ich infestation that is already ON fish, or cure a bacterial disease fish may have.
Should never be run when treating with any drugs or medications.
UV can also alter the structure of some dissolved chemical compounds.
UV light can be damaging to the human eye, so DO NOT look into the bulb.
Always unplug the unit when working on it to prevent possible shock if it breaks or gets wet.
To be effective, UV Sterilization (UVS) must expose the germs to high enough
light intensity for a long enough period of time. Martin Moe cites 35,000
to 100,000 microwatts per second per square centimeter as the norm. The
most effective UV light is the high energy UV(C) light roughly at the
wavelength of 250 Angstrom. Common problems which can reduce the kill rate
of the germs are:
1) Allowing the water to flow too fast past the UV light.
2) Light blockage due to a build up of salt deposits or
bacterial slim on the bulb.
3) Fading of the light due to age of the bulb (which
typically have a six month life.)
The same property of this light that kills germs can damage your eyes, and
special care must be taken to avoid direct or indirect eye contact with this
light. The UV(C) light does not penetrate water very well, so to be
effective, UV Sterilizers commonly position the UV bulb close to the water
which also can pose a risk of electrical shock should the bulb break, etc..
There are three types of UV Sterilizers:
1) Tray type. (Typically homemade) with UV bulbs suspended in a reflecting
fixture over a shallow tray of slow flowing water. Benefits; easily
cleaned, can be cheap, can be made large enough for commercial applications.
Problems; safety risks to your eyes, too large and awkward for many home
uses.
2) Tube type, wet bulb. Tube types have the benefit of exposing all sides
of the fluorescent tube to water with no reflector. The water passes
directly past the bulb which is mounted in a waterproof tube. Benefits;
cheap, compact & effective. Problems; difficult to clean the slime
accumulations from the bulb, safety risks due to electrical shock.
3) Tube type, dry bulb. Similar to above, but the UV tube is surrounded by
a quartz tube [glass blocks UV(C) light] insulating it from the water.
These are more expensive and probably safer. Changing the light bulb is
more easy, and dry bulb tube types can have a internal device to wipe slime
from the quartz tube.
Suggested wattages are 4-8 watts for 20-40 gallon aquariums, 20-25 watts for 50-100 gallons, and 40 watts for larger aquariums. Using this method of treating water is quite controversial amongst aquarists. Some consider it to be a waste of money, not all that effective, or suitable for fish-only, but unnatural for reef tanks, while others feel it does have its benefits for either type of system.
The general consensus is that an aquarist that has a well maintained and uncrowded aquarium, as well as follows good quarantine procedures when introducing new specimens to their system, a UV light filter is not necessary. For those that may be deciding on whether a UV light filter should be added or not, here are some other points to consider.
Most effective when run 24/7.
Most effective if the water is clear.
Most effective if bulb is new, or replaced regularly (at least every 6-8 months).
Most effective if the UV light penetrates less than one inch of water.
Effectiveness can be hindered if the water passes to fast past the bulb. Most effective if the exposure time of the water to the UV light is longer than one second.
The effectiveness of UV light can be hindered if there is light blockage, i.e. a salt encrusted bulb.
It can help to prevent future water borne pathogen reoccurrences, once the initial problem as been completely eradicated from the aquarium.
UV light not only kills unwanted organisms, but beneficial ones as well.
Because it can destroy beneficial microscopic organisms that some reef tank inhabitants may depend on as a food source, UV light should not be run during feeding time.
It only destroys organisms that are free floating IN the water as it passed by the UV light, i.e. it will NOT get rid of an ich infestation that is already ON fish, or cure a bacterial disease fish may have.
Should never be run when treating with any drugs or medications.
UV can also alter the structure of some dissolved chemical compounds.
UV light can be damaging to the human eye, so DO NOT look into the bulb.
Always unplug the unit when working on it to prevent possible shock if it breaks or gets wet.
To be effective, UV Sterilization (UVS) must expose the germs to high enough
light intensity for a long enough period of time. Martin Moe cites 35,000
to 100,000 microwatts per second per square centimeter as the norm. The
most effective UV light is the high energy UV(C) light roughly at the
wavelength of 250 Angstrom. Common problems which can reduce the kill rate
of the germs are:
1) Allowing the water to flow too fast past the UV light.
2) Light blockage due to a build up of salt deposits or
bacterial slim on the bulb.
3) Fading of the light due to age of the bulb (which
typically have a six month life.)
The same property of this light that kills germs can damage your eyes, and
special care must be taken to avoid direct or indirect eye contact with this
light. The UV(C) light does not penetrate water very well, so to be
effective, UV Sterilizers commonly position the UV bulb close to the water
which also can pose a risk of electrical shock should the bulb break, etc..
There are three types of UV Sterilizers:
1) Tray type. (Typically homemade) with UV bulbs suspended in a reflecting
fixture over a shallow tray of slow flowing water. Benefits; easily
cleaned, can be cheap, can be made large enough for commercial applications.
Problems; safety risks to your eyes, too large and awkward for many home
uses.
2) Tube type, wet bulb. Tube types have the benefit of exposing all sides
of the fluorescent tube to water with no reflector. The water passes
directly past the bulb which is mounted in a waterproof tube. Benefits;
cheap, compact & effective. Problems; difficult to clean the slime
accumulations from the bulb, safety risks due to electrical shock.
3) Tube type, dry bulb. Similar to above, but the UV tube is surrounded by
a quartz tube [glass blocks UV(C) light] insulating it from the water.
These are more expensive and probably safer. Changing the light bulb is
more easy, and dry bulb tube types can have a internal device to wipe slime
from the quartz tube.
