UV... any down sides???

[TwoTankAmin]

I have a small UV unit. I got it when I began working with Altum Angels. They are wild caught fish from very acid waters where many bacteria cannot survive. As a result, the Altums are not exposed to a lot of diseases. When they arrive here they are very vulnerable. They are difficult to even keep alive as their immune systems are not up to par since they have not been greatly used until they leave home and get into waters with nasties in them.

So, on my second try I had the UV unit. I also started with a brand new tank, water etc. etc.

I had to learn a lot about UV before I felt confident about how to use one properly. For that, I read a ton on the site where I finally bought mine. What is below is a quote, and the place to go to read much more great info on this subject us the link at the end of the info below.

Here are a few BASIC points as to what a Properly Installed, Well Designed TRUE UV Sterilizer (or Sterilizer) Can Do for your POND or AQUARIUM:

• Clear Green Water in Aquariums or Ponds when run in parameters for clarification. Clarification is the simplest use of a UV Sterilizer and in fact many if not most UV Sterilizers are ONLY capable of clarification, which is why many are misnamed "UV Sterilizer" when in fact these lower end models are actually just "UV Clarifiers". It is noteworthy that a true level 1 capable UV Sterilizer will also clear green water in ponds much more quickly and maintain water clarity MUCH better than a basic UV Clarifier!!!

• Kill most suspended bacteria and many viruses in the water column when run at level 1 or 2 Sterilization, while not affecting bacterial colonies in filter media and substrate

• Kill Epistylis in the water column which feed on bacteria in the water column before attaching to fish. The Epistylis is ciliate distantly related to Ich, which it is commonly confused with. My experience with Epistylis is that in an aquarium utilizing true level one or higher UV Sterilization, is that Epistylis infestations are 99.9% nonexistent!

• Improve Redox Balance in aquarium or pond in part by lowering oxidative stress and thus improve the fish’ ability to fight disease (this has been proven in well researched human studies too)

• AID in the control of parasites such as Ich or Cryptocaryon by improving immune function and at very low flows can more directly aid in parasite control in the water column, although not on fish directly (that requires Level 2 Sterilization; under 8-12 gph per watt, which is still not 100%).

• Stop the spread of toxic red tide dinoflagellates which can make humans very ill and has recently been shown to infect home/office marine aquariums. These red tide dinoflagellates have been shown to be effectively destroyed by either level one or higher UV Sterilization or an ozonizer connected to a Protein Skimmer (much more so than by chlorine).


To read more than you knew existed on this subject and good advice on how to chose the right unit for your needs (if you have them), here is a link to all the great info you could want: https://www.americanaquariumproducts.com/sterilization.html

 

[Byron]

So when people use them on quite expensive set ups do you think its more of a placebo effect than doing any real benefit? I'm not looking for excuses not to do water changes - far from it - I've just always thought / hoped having UV would be in addition to the other standards of care you've mentioned?

I would never use UV because there is no proven factual evidence that it does nothing really beneficial. It may deal with unicellular algae (green water) and this works basically because the algae here is free floating. But there is the same problem, not all of it can get through the UV if the "clean" water keeps getting returned to the aquarium. Eventually I suppose it will work sufficiently but it seems much easier to me to dal with green water naturally. As for bacteria and parasites, useless. Yes, people may think it works on these, but there are other factors and it wold be impossible to credit the UV with success with a problem that it cannot possibly solve by its very nature.

Back to my city water which runs through UV...the nitrifying bacteria still get through in some level, so obviously UV is not 100% effective on these. Waste of money.

Edit: After I posted this, @TwoTankAmin post came up, and I don't think we are differing here, but if we are in any respect I accept his view on this because he knows much more about it than I do. I don't think anything I wrote disagrees substantially.

 

[TwoTankAmin]

For me to know how and what to use I had to learn how to do the calculations for wattage and flow rates to achive the different levels of kill. It starts with algae that is in the water and moves into the parasites, bacteria and viruses. Along this specturm the wattages go up and the dwell time gets longer. Dwell time has to do with the length of the UV light light and hence exposure time spent passing through the system and then to how rapidly the water moves through the unit combined with the strength of the bulb.

UV has been used for some time in aquariums and aquacullture. If you are curious there is a lot of research on disinfection of aquarium water. Often UV is use with other methods. Ozone is also used. One of the more important factors in determining the efficacy of UV is how clean the water is. The more particles (turbidity) in the water water, the less effective UV is as the particles block the light.

Whether one needs to use a UV unit depends on some very specific conditions. I have never used my unit for anything except for what I got it- to make a tank safe for wild Altums. UV is similar to medications. Neither should be used except as needed. I most often find research papers tend to relate to aquaculture or other intense stocking as these are more likely to have problems which need such a solution.

My UV unit was sized to work in a max. of a 29 gal tank. However, I did also run it for a while on a 55 being set up to receive Altums. I had plenty of time to run it and minimal pathogens with which to deal. Most of us do not need to use UV, especially not full time. But if you think you might, read the heck out of the link I posted as you will for sure come through it knowing if you need UV and if so how much and what brands and bulbs are decent.

Basically, UV works by breaking down DNA. "Higher-energy UV rays are a form of ionizing radiation. This means they have enough energy to remove an electron from (ionize) an atom or molecule. Ionizing radiation can damage the DNA (genes) in cells,"

 

[anewbie]

Perhaps a better title for this thread would be "any positives" rather than any downsides. In freshwater UV is so limited it is frankly useless. Green water can sometimes be improved with UV but it depends upon the severity.

In order for UV to be effective, all the water in the tank must pass through the UV and not then return to the tank until all the water is out. Otherwise any parasites, protozoan, etc. in the water will not be forced through the UV. I really would not waste the money. And I am certain in a previous thread on this topic it was mentioned that UV is carcinogenic.

One obvious positive for a very strong uv is that it will kill pathogen/parasite. We are talking around 35-40 watt range. I run one on my qt aquarium.

 

[Oddball59]

UV lights do work very well, and don't "kill" algae it renders the spores impotent so they don't spread, they won't kill algae attached and growing like hair algae or any other, they will kill green algae.
But UV lights also kill good nitrifying bacteria, so shouldn't be switched on a new cycling tank until it's established, I've spoken to a few companies and their advice is tits on a bull... some say don't use for the first four days, others say the first month. Again this is because it will kill the bacteria your trying to grow.
The efficacy of UV depends upon the strength of the UV tube, the length of the tube and the flow of water.
I have worked on many UV systems over the years through work and they are effective. In my case it Was part of the process of creating potable water on ships, coming through a huge RO system.
But they were incorporated to kill bacteria that might have harmed us as we drank ship board water. I have heard of ships crews being pretty poorly and the reason was a failure to maintain a UV system.
So I know from talking to reps and engineers in the industry that they definitely kill bacterias, which will include the beneficial bacteria. 35 Years experience.

What I don't know is when to switch them on, on a fresh tank? Obviously culturing the bacteria is something we need, and we don't want UV killing it before it can establish itself on substrate, filters etc... If you dump a capful or two of bacteria and that goes through your filter then UV before establishing itself your asking for trouble.
If anyone can come up with a definitive answer as to when to first switch on the UV I'd love to hear it? (I'd err on caution. Four days sounds far too quick, maybe not. It's all down to the time bacteria takes to establish itself.

Are UV filters good? Yes.

Certainly never use a UV filter inside the tank. Always inline on the filter outlet, or if you have a HOB you can use a pump to circulate water again through a Uv installed on the output.

 

[anewbie]

I switch

UV lights do work very well, and don't "kill" algae it renders the spores impotent so they don't spread, they won't kill algae attached and growing like hair algae or any other, they will kill green algae.
But UV lights also kill good nitrifying bacteria, so shouldn't be switched on a new cycling tank until it's established, I've spoken to a few companies and their advice is tits on a bull... some say don't use for the first four days, others say the first month. Again this is because it will kill the bacteria your trying to grow.
The efficacy of UV depends upon the strength of the UV tube, the length of the tube and the flow of water.
I have worked on many UV systems over the years through work and they are effective. In my case it Was part of the process of creating potable water on ships, coming through a huge RO system.
But they were incorporated to kill bacteria that might have harmed us as we drank ship board water. I have heard of ships crews being pretty poorly and the reason was a failure to maintain a UV system.
So I know from talking to reps and engineers in the industry that they definitely kill bacterias, which will include the beneficial bacteria. 35 Years experience.

What I don't know is when to switch them on, on a fresh tank? Obviously culturing the bacteria is something we need, and we don't want UV killing it before it can establish itself on substrate, filters etc... If you dump a capful or two of bacteria and that goes through your filter then UV before establishing itself your asking for trouble.
If anyone can come up with a definitive answer as to when to first switch on the UV I'd love to hear it? (I'd err on caution. Four days sounds far too quick, maybe not. It's all down to the time bacteria takes to establish itself.

Are UV filters good? Yes.

Certainly never use a UV filter inside the tank. Always inline on the filter outlet, or if you have a HOB you can use a pump to circulate water again through a Uv installed on the output.

Mine is very strong - 40 watts; and i switch it on when adding new fishes. It is for killing parasite/bacteria that might be on the fish but not detected during qt - from my reading 40 watts or more is required to be effective against parasites but a lot also depends on flow of water through the uv.

 

[Oddball59]

I switch

Mine is very strong - 40 watts; and i switch it on when adding new fishes. It is for killing parasite/bacteria that might be on the fish but not detected during qt - from my reading 40 watts or more is required to be effective against parasites but a lot also depends on flow of water through the uv.

Kia Ora, Hi. It doesn't matter what the flow is or length of the lamp, it is only efficacious if the water passes directly past the lamp, unless you can make your fish swim past the uv light, which will kill it, which you can't, a UV lamp can't cure something already on the fish. It will prevent any parasites from the fishes illness in the water spreading but it really can't fix something already on the fish. Medication and water changes are needed. Quarantine and treatment is the best thing you're right. But the UV can only stop the illness if it gets into the water itself. Not having a go mate just trying to help. UV is great for anything water born. As I posted out the length of the lamp, water flow and lamp strength is the most important things. because it kills parasites and illness causing bacteria in the water itself its a good idea to run it with new fish, but you need to be sure it's on long enough for all the tanks water to flow past. I prefer to leave it on all the time, I believe this is true because it is very good at stopping algae, it doesn't kill algae but makes the algae spores impotent so it can't reproduce and spread. Any algae already grown on plants or substrate or hardscape won't be solved by UV, so UV is a part of a process and you need other ways of curing the algae... cutting it out, physically removing it, scrubbing it off hardscape with say a tooth brush will allow it to flow through the mechanical filter and UV. Water changes are the best cure for algae alongside a UV.
The chemical cures for algae are very extreme and needs great care, a lot of it out there is snake oil. But for your poorly fish, medication is best and works well. And you're doing exactly the right thing isolating the new ill fish. Just know that there is no doubt UV will not help "cure" an already infected fish. All the best. Kia Kaha. Phil. Hope this helps.

 

[Oddball59]

For me to know how and what to use I had to learn how to do the calculations for wattage and flow rates to achive the different levels of kill. It starts with algae that is in the water and moves into the parasites, bacteria and viruses. Along this specturm the wattages go up and the dwell time gets longer. Dwell time has to do with the length of the UV light light and hence exposure time spent passing through the system and then to how rapidly the water moves through the unit combined with the strength of the bulb.

UV has been used for some time in aquariums and aquacullture. If you are curious there is a lot of research on disinfection of aquarium water. Often UV is use with other methods. Ozone is also used. One of the more important factors in determining the efficacy of UV is how clean the water is. The more particles (turbidity) in the water water, the less effective UV is as the particles block the light.

Whether one needs to use a UV unit depends on some very specific conditions. I have never used my unit for anything except for what I got it- to make a tank safe for wild Altums. UV is similar to medications. Neither should be used except as needed. I most often find research papers tend to relate to aquaculture or other intense stocking as these are more likely to have problems which need such a solution.

My UV unit was sized to work in a max. of a 29 gal tank. However, I did also run it for a while on a 55 being set up to receive Altums. I had plenty of time to run it and minimal pathogens with which to deal. Most of us do not need to use UV, especially not full time. But if you think you might, read the heck out of the link I posted as you will for sure come through it knowing if you need UV and if so how much and what brands and bulbs are decent.

Basically, UV works by breaking down DNA. "Higher-energy UV rays are a form of ionizing radiation. This means they have enough energy to remove an electron from (ionize) an atom or molecule. Ionizing radiation can damage the DNA (genes) in cells,"

Kia Ora, Absolutely a great description, but it does no harm to leave the UV on all the time to ensure the whole water mass flows past it I do this and to ensure algae can't reproduce. You're absolutely right, do your research and get the best filter you can, wattage and I would say an inline straight filter is best as there is no restriction on water flow, its a catch 22 I feel because we measure how good our filters are because of the amount of water the filter can process, we aim for a high figure here yet we want preferably a slower pace past the UV.

I love you have researched the science. However I know quite a high flow is possible with the right wattage UV. We used them all the time at work when I was a Marine Electrical Officer (35 years), and we'd have big banks of the old UV tubes and a very fast water flow. Later we had huge RO systems retro fitted, But as I said there were typically at least half dozen large 3ft UV lamps. But I did talk to engineers reps for the UV companies who told us horror stories of ships companies all going down with diarrhoea because their engineers had not kept their eye on the UV as part of routine maintenance, which I always had on my list, a bi weekly check of all lamps. These poor guys had lost all their lamps and not known it. So the potable water wasn't sterilised well enough to drink

And yes many have no problems with no UV filter, water changes are just as essential to controlling algae. But UV is great for me in a belt and braces sort of way. But no one has yet addressed my question about when to start using UV on a new cycling tank, as it will kill the nutrifying bacteria we are trying to grow. Do you have any information on that Amin? Hope your well mate, Kia Kaha. Phil.

 

[Byron]

UV does not and will not kill most of whatever is in the water because all the water cannot pass through it into a second aquarium. My city water is treated with UV, but it is effective because the water leaves the reservoir, passes through the UV, and then disperses through the water mains. It does not go back into the reservoir to be reinfected as it does in an aquarium.

 

[anewbie]

Kia Ora, Hi. It doesn't matter what the flow is or length of the lamp, it is only efficacious if the water passes directly past the lamp, unless you can make your fish swim past the uv light, which will kill it, which you can't, a UV lamp can't cure something already on the fish. It will prevent any parasites from the fishes illness in the water spreading but it really can't fix something already on the fish. Medication and water changes are needed. Quarantine and treatment is the best thing you're right. But the UV can only stop the illness if it gets into the water itself. Not having a go mate just trying to help. UV is great for anything water born. As I posted out the length of the lamp, water flow and lamp strength is the most important things. because it kills parasites and illness causing bacteria in the water itself its a good idea to run it with new fish, but you need to be sure it's on long enough for all the tanks water to flow past. I prefer to leave it on all the time, I believe this is true because it is very good at stopping algae, it doesn't kill algae but makes the algae spores impotent so it can't reproduce and spread. Any algae already grown on plants or substrate or hardscape won't be solved by UV, so UV is a part of a process and you need other ways of curing the algae... cutting it out, physically removing it, scrubbing it off hardscape with say a tooth brush will allow it to flow through the mechanical filter and UV. Water changes are the best cure for algae alongside a UV.
The chemical cures for algae are very extreme and needs great care, a lot of it out there is snake oil. But for your poorly fish, medication is best and works well. And you're doing exactly the right thing isolating the new ill fish. Just know that there is no doubt UV will not help "cure" an already infected fish. All the best. Kia Kaha. Phil. Hope this helps.

Yes of course it keeps it from spreading that is obvious but this is important for a lot of diseases that go through phases will become water borne. If it was obvious the fish had a disease then it would have been treated during qt; but a lot of diseases are not 'obvious'. Also the amount of time the water spends around the uv is very important when it comes to killing bacteria or parasite. Saying lamp strength is important is a useless metrics - after all what is 'strong' to one person is 'weak' to another. Specific data points are important - the same can be said about flow but i didn't memorize those values when i set the system up only hte recommended wattage for the uv lamp. My uv unit are self contained and pumps pass the water through the uv system. Btw TB is another bacteria that UV lamps will kill...

 

[OnlyGenusCaps]

I love my hang on UV lamp setup for my QT. Won't kill what's on the fish, but it'll hit the open water stages of most stuff disrupting the cycle and often sparing new fish from being hit (get those ich tomonts and theronts!). I will say, I've had one experience that made me realize I need to think about how I use it. I added it to a marine QT that had gotten green with a phyto bloom. I wanted to clean it up for a new round of coral QT, so I popped the UV on it. It worked so well and so quickly, that all of the dead phyto clouded the water and I got a small ammonia spike. It's a pretty specific case, but if you have enough biomass you are killing with it, be careful about the subsequent water conditions. Otherwise, UV is great! If a bit expensive.

 

[Oddball59]

UV does not and will not kill most of whatever is in the water because all the water cannot pass through it into a second aquarium. My city water is treated with UV, but it is effective because the water leaves the reservoir, passes through the UV, and then disperses through the water mains. It does not go back into the reservoir to be reinfected as it does in an aquarium.

Kia Ora, Hi Byron. You're right I think uptp a point, if the UV is running none stop it will eventually have mades enough passes to have cleared the water. I think some algae are tough and more then one pass will need to be made and it will over time clear your tank as long as growing algae is removed! But... I don't believe it can then be turned off. if we're talking algae the UV filter is only ever going to be a part of a process as attached algae will continue to produce the spores UV will make inert.

Reading a lot of peoples posts they think UV is actually in the "tank" water and floats around killing stuff. I think it's subjective I'm a big fan, as I have a lot of experience with UV over the years on big systems to make potable water for humans, the same arguments for use apply to fish/tanks.

water changes, physical removal etc... or you can run the biggest UV in the world and it won't ever clear your tank.
So UV. is just a tool which is part of a greater system, which is how I view it.

 

[Magnum Man]

something else I'm curious about...
can organisms get UV resistant??? in a way that some diseases get resistant to antibiotics, or like get UV "tanned" so they don't burn as easy, like we do to the suns rays???

 

[Colin_T]

Not normally. If a microscopic organism is exposed to enough UV light, it should die. If it isn't exposed to enough UV light, then in my opinion it could survive but is unlikely to become resistant. Having said that, I don't think anyone has really done a lot of research into that question so they might become UV resistant if they pass through the light and not die.

 

[Oddball59]

something else I'm curious about...
can organisms get UV resistant??? in a way that some diseases get resistant to antibiotics, or like get UV "tanned" so they don't burn as easy, like we do to the suns rays???

Kia Ora Magnum...I doubt this very very much, UV is very powerful and what you are talking about it rendering harmless in the case of algae spores which it doesn't "kill" but renders impotent as it were so the spores can not reproduce and just die away through their normal cycle. Anything smaller it will kill... including your useful bacteria... which is why you shouldn't run your UV until the tank is cycled and the bacteria established. Given that it would also kill any harmful micro organisms. Don't forget when your tank is established the "good" bacteria is living on substrate, filter sponges and hardscape etc... and is not free floating... if it was the UV would kill it.

It will kill any micro organisms that may attack your fish and damage their health, it will clear free floating green algae, by neutralising it until it dies of inability to reproduce and the filter can then clear it out without having to battle it's reproductive cycle. Hair type algae it will also kill the spores but as the algae is growing on plants and hardware it's still able to reproduce... those spores are again killed, but the hair type algae present or algae growing flat on hardscape will need removing manually, and with lots of water changes. I'm afraid removing this will mean actually scraping or brushing the algae off, with a wire brush, a tooth brush, water proof electric ones are good. just releasing it so the filter can do it's job alongside water changes of about %50.

You can try chemical methods, but many are just snake oil and others are so aggressive they'll also affect your plants, so manual removal and water changes with your UV running 24 hrs.
UV is very powerful, I once made the mistake of looking at a UV light for a few minutes and had headaches, felt sick, and my eye's were killing for a full day.
The only downside to UV assuming you've got one powerful enough for your water volume, a straight... inline one to maintain water flow placed on the outlet pipe from your filter if you have a canister, or on the outlet of a circulating pump if you have a HOB is making sure you have good seals on the pipes and filter. No problem really, pipes, jubilee clips, job done.
But just leave it on all the time. It does no harm they're very low wattage, keeps you safe from anything nasty you may introduce accidentally or would grow naturally like algae if your lights are too strong, or your getting a lot of natural light, have a look but they are rated to run continuously, because that's what they're designed for, for maybe three years before you need a lamp change or new unit, you may get even longer it depends on the quality.
You're not getting anywhere just switching it on for say four hours a day, the rest of the time things can creep in establish themselves and begin a growth cycle which UV won't stop.
Put it in, switch it on and forget it, just glance at it every now and then to make sure the lamp is still on, that's all there is to it. Hope this helps. Kia Kaha. Phil.