UV sterilizers in a different light

[nuclearheli]

UV has been around for a long time and has been studied significantly in various applications due to its popularity. Applications where UV is most effective are used in single pass system as water sterilizer. Unfortunately (even assuming a 100% kill rate all the time), a reef tank is a not a single pass system which render UV relatively ineffective especially as control for bacteria or pathogen spread.



Despite what you believe, the data show otherwise.

Pathogen Reduction in Closed Aquaculture Systems by UV Radiation: Fact or Artifact?


The efficacy of UV irradiation in the microbial disinfection of marine mammal water.


Ultraviolet light control of Ichthyophthirius multifiliis Fouquet in a closed fish culture recirculation system


UV is really not affective as either control or eliminiate ich in a recirculating system.

I do appreciate you bringing these papers to light. Did you actually read the papers? Since reading technical articles is a requirement of my job not just a hobby I actually purchased and read the articles, not just the abstracts.

So reference 1. Good paper and I agree with the paper. This however is a theoretical assumption based on mathematical equations, which again I happen to agree with. But it is not real world which may produced different results. It does however support one of my original conclusions if you read my post:

Therefore over time, perhaps a long time my theory is that the population has been either eliminated or reduced to such a small size that it has had no effect on my tank.

The paper implies that based on the equations the population probably does not approach zero however the results show a significant mathematical reduction in the population size. It also does not take into account the wavelength and intensity of the UV source.

Reference 2: Does not apply to this conversation. It deals with the reduction of yeasts and bacteria, not parasites such as Ich. The effectiveness of UV is well known for bacteria, yeasts and other parasites. This article is not relevant.

Reference 3: This one surprised me. I am not sure how you missed the conclusions of this article. I give you a quote from the general discussion of the paper.

The incorporation of a UV light source into this closed system significantly (P < 0-005) reduced deaths due to /. multifiliis and, in fact, no /. multifiliis were identified in the fish in the test aquaria (Table I). These results indicate that the incorporation of a UV light into the system could have immediate practical benefits for individuals who are using multi-aquarium closed systems.

This paper also contains a world of information on the effect of UV on bacterial populations and water quality along with the minimum UV requirements in terms of wave length and intensity. I could be reading this article wrong since my field of expertise is physics, not marine biology, I will admit that. This article as opposed to reference 1 is actual real world data. I would publish the full paper but it is copyright protected. The only difference in this study is the use of multiple aquariums. I can't publish the setup but it is a closed system almost exactly the same as my setup except for the use of multiple tanks. I cannot find any reference material to a study like this with a single tank but I believe you can apply the same conclusions.

And to clarify another comment, can't remember from which post, I am not dismissing other forms of treatment for ich, in fact I said many times that this may also be an alternative treatment, not the only treatment.

 

[geaux xman]

@ Nuclearheli

If you dont mind, which UV unit and wattage are you using. Roughly how much flow do you have going thru it?

 

[nuclearheli]

@ Nuclearheli

If you dont mind, which UV unit and wattage are you using. Roughly how much flow do you have going thru it?

I can't say at the moment which model I have, I am not at home right now. However from the article I quoted this is the model and wattage they used:

The UV light sterilizer is an Aquafine model MP-2-SL (Aquafine Corporation, Valencia, California, U.S.A.) which generates 2650 (uW/cm^ of UV light.

Obviously the manufacturer is not important, just the specifications of the unit.

My UV light is located in the same exact location as the article setup, the last item in the return flow. 100% of my return water goes through the UV light. My return pump is a Blueline HD 100 with a published maximum flow of 1,900 gph. However I do take some of the return water to supply my fuge and I have a small manifold to provide supply water to various reactors when and if I need to use them. I would guess that my return flow is no less than 1500-1600 gph to the DT, but I am not sure. My skimmer runs off of a separate blueline 30 HD-X 1" so that is not a factor.

 

[nuclearheli]

@ Nuclearheli

If you dont mind, which UV unit and wattage are you using. Roughly how much flow do you have going thru it?

One more thing from the article that may help answer your question:

The flow rate of the water was 7-5 gallons/min

 

[LobsterOfJustice]

I personally have given up on the idea of an ich free tank, I have had ich pop up even after hypoing the DT and treating all fish in QT with copper. You'd have to QT every rock, snail, and coral fishless for 8 weeks too.

I'm considering a UV, I probably won't run it 24/7. It would be good to have it plumbed up and ready to go, and it can be plugged in when you see a few spots or when you introduce new fish (I am still going to QT - I just know my tank isnt ich free). I don't expect it to eliminate ich from the tank, but it might help with outbreaks. I also agree with the idea that if people say it's not efficient enough to kill all the ich, then its not efficient enough to kill all your beneficial stuff either - you can't say it will kill all your good stuff and not kill ich.

My return pump is 1700 GPH, and I like to oversize my equipment (i.e. want a unit that is rated for a flowrate of at least 2000gph) - does anyone have recommendations? Looking at the Lifegard 80w.

 

[geaux xman]

From what I've read about UV, you would want a much lower flow rate for a more effective kill rate for ich. Somewhere in the less than 1000gph range even with an 80w unit.

Here Smart HO UV recommends 450-600gph for an 80w unit for parasites.
http://www.emperoraquatics-aquarium.com/smarthouv.php#80watt.

I think far too many people run too small of a unit with too fast of a flow rate. I got a couple of local buddies with all sorts of ich problems b/c of this.

I would also run it 24/7 so you can catch the parasites when its going thru its stages. For instance, lets say theres 1000 ich ogranisms in a tank. 200 of it might be at the 1-10 day stage of the cycle, another 200 at the 10-20 day stage and the rest at the 20-30day stage. So not all of it is in its free swimming stage at the same time.

Any lapse with the UV being off just decreases the UV's effectiveness.

JMO.

 

[dzhuo]

So reference 1. Good paper and I agree with the paper. This however is a theoretical assumption based on mathematical equations, which again I happen to agree with. But it is not real world which may produced different results. It does however support one of my original conclusions if you read my post:

Therefore over time, perhaps a long time my theory is that the population has been either eliminated or reduced to such a small size that it has had no effect on my tank.

A theoretical assumption set up to model a bacteria colony and grow model and went on to demonstrate (via differential equations) how affective UV would have on the colony in a recirculating system is not good enough and yet your assumption that UV will eventually be able to control the spread is sound? OK.

It also does not take into account the wavelength and intensity of the UV source.

Because it doesn't matter. It's not how affective the UV will be. In fact, most UV are very effective on what they are designed for and that's why UV has a wide applications used in water sterilization and water treatment system. In such single pass system (every single drop of water has to pass the UV before it moves to another container or treatment stage), UV is very effective. In a recirculating system, it's not and that's not because of set up issues (wrong wavelength, flow rate or intensity as you focused on), it's because the unit will not be able to discharge water fast enough to control an exponential bacteria grow. The key point is whether UV is a suitable tool in a recirculating system (ie, your tank); not if UV itself dosen't function as it's designed.

Reference 2: Does not apply to this conversation. It deals with the reduction of yeasts and bacteria, not parasites such as Ich. The effectiveness of UV is well known for bacteria, yeasts and other parasites. This article is not relevant.

See above discussion. This is the most relevant of the 3 articles I cited. It demonstrated that UV is effective, +70% kill rate on any inbound water, and yet has almost no impact on the entire system.

Reference 3: This one surprised me. I am not sure how you missed the conclusions of this article.

I didn't miss the conclusions of the article. The abstract is perfectly stated and a good summary of the finding of the study. Despite what you believe, the abstract and conclusions (or the quote you cited) don't conflict.

I give you a quote from the general discussion of the paper.

The incorporation of a UV light source into this closed system significantly (P < 0-005) reduced deaths due to /. multifiliis and, in fact, no /. multifiliis were identified in the fish in the test aquaria (Table I). These results indicate that the incorporation of a UV light into the system could have immediate practical benefits for individuals who are using multi-aquarium closed systems.

It has been many years since I left academic so I will have to recall this from memory. The quote you cited is not surprise. In fact, if UV is not able to kill a significant of micro-organisms it's designed to kill, it will have no applications and disappear from the market. What this mean is that if you have 2 tanks. One is known to have ich and you connect a second tank to it. In this single passage, you install the UV (properly setup to kill ich and assuming 100% kill rate all the time) so every drop of water pass the UV before it gets to the second tank. The quote demonstrated that the second tank (and the fish) is ich free.

I can't publish the setup but it is a closed system almost exactly the same as my setup except for the use of multiple tanks. I cannot find any reference material to a study like this with a single tank but I believe you can apply the same conclusions.

The set up is important because it mirrors a recirculating system (your tank); not a single-pass (think RO/DI).

 

[nuclearheli]

A theoretical assumption set up to model a bacteria colony and grow model and went on to demonstrate (via differential equations) how affective UV would have on the colony in a recirculating system is not good enough and yet your assumption that UV will eventually be able to control the spread is sound? OK.



Because it doesn't matter. It's not how affective the UV will be. In fact, most UV are very effective on what they are designed for and that's why UV has a wide applications used in water sterilization and water treatment system. In such single pass system (every single drop of water has to pass the UV before it moves to another container or treatment stage), UV is very effective. In a recirculating system, it's not and that's not because of set up issues (wrong wavelength, flow rate or intensity as you focused on), it's because the unit will not be able to discharge water fast enough to control an exponential bacteria grow. The key point is whether UV is a suitable tool in a recirculating system (ie, your tank); not if UV itself dosen't function as it's designed.



See above discussion. This is the most relevant of the 3 articles I cited. It demonstrated that UV is effective, +70% kill rate on any inbound water, and yet has almost no impact on the entire system.



I didn't miss the conclusions of the article. The abstract is perfectly stated and a good summary of the finding of the study. Despite what you believe, the abstract and conclusions (or the quote you cited) don't conflict.



It has been many years since I left academic so I will have to recall this from memory. The quote you cited is not surprise. In fact, if UV is not able to kill a significant of micro-organisms it's designed to kill, it will have no applications and disappear from the market. What this mean is that if you have 2 tanks. One is known to have ich and you connect a second tank to it. In this single passage, you install the UV (properly setup to kill ich and assuming 100% kill rate all the time) so every drop of water pass the UV before it gets to the second tank. The quote demonstrated that the second tank (and the fish) is ich free.



The set up is important because it mirrors a recirculating system (your tank); not a single-pass (think RO/DI).

This is not worth discussing any longer since your conclusions are apparently based on the abstract, mine are based on the full article. It does make a big difference if you are modeling bacteria or a parasite. As the article clearly states, the size of the parasite is critical to the conclusions. Now I realize that most solid research begins with rats rather than humans however it has been shown over and over again that in some cases the results seen with the test subject is not always what you see in the target subject. And I beg to differ, the wavelength and resident time is critical. Regardless, I believe the conclusions of the author are accurate and I also believe I have seen the same results in my tank. I do know how to interpret technical articles and I believe I have interpreted this article correctly. Fortunately there is no law against using UV in this hobby, only personal opinions. I will keep the light burning, as the saying goes. Good night to all and enjoy the thread. Time to move on.

 

[j tavares]

Here is my thought on Uv I never used it for the first 20 years and NOW I will not be without it. The fish are healthier, no loss in two years , the fish look like they are suspended in air, the bad guy algae , well there is none, nada, zilch and the only change I made in the last two years was I added a Uv sterilizer to my 150 fowlr tank. No negatives on my end.

 

[Hdhuntr01]

There is plenty of talk about UV Sterilization. Few people really understand the concept or how it should work. Brand is fairly important. There are a few companies that specialize in UV Sterilization and then a bunch of companies that are trying to build something cheap to sell to aquarium hobbyist. Then you want to look at Watts, that basically compares to size. In order to effectively kill, water must be passed through at a specific flow per Watt. In other words, if you have a 15 Watt Sterilizer and run 1000 GPH through it, you accomplish absolutely NOTHING. The technical formula is (microwatt seconds per square centimeter). The basic standard is for ca. 400GPH Flow use ca.15 Watts, for ca. 1000GPH Flow use ca. 40 Watts and for ca. 1500GPH Flow use ca. 60 Watts. Basically you are looking for a certain dwell time. Different dwell times are required to kill different organisms. 75,000 to 90,000 is what is needed to kill most fish diseases / parasites. If you go more, you end up killing off planktonic food supply and beneficial bacteria in your system. The more flow past a specific wattage UV Bulb, the less effective and vice a versa, the less flow across a specific wattage UV Bulb the more effective it is in destroying micro organism. So if you have too little flow you kill off everything good and bad. If you have too much flow, you are doing nothing.
There is also another use for a UV Sterilizer. You can use one in conjunction with an Ozone Reactor. The output of the Ozone Reactor is passed through the UV Sterilizer to ensure all excess Ozone is eliminated "killed off". Most people accomplish this by passing the output of the Ozone Reactor over or through Carbon. Not that I want to debate this but I am a firm believer that Carbon is harmfull to your tanks inhabitants. And there are many other who believe the same. So in order to achieve a clean environment, Ozone is used and a UV Sterilizer is then used to burn off any excess Ozone so as not to harm the tank's inhabitants.

 

[dzhuo]

This is not worth discussing any longer since your conclusions are apparently based on the abstract, mine are based on the full article.

Your conclusions are based on a quote you misinterpreted and I pointed that out to you. Not every single drop of water will pass the UV entering the sump. Similarly, not every drop of water will pass the UV from the sump entering your display either. If this is the set up you have then yes UV can be very effective controlling the spread.

Carbon is very effective as water purifier but if you use a single oz of it in a 4000g tank, I will argue it does nothing but not because the carbon suddenly lose the ability to absorb but because it's disproportionally inadequate. There are always more organic matters produced in a 4000g tank for a 1oz of carbon to absorb even assuming the carbon is never exhausted. I am not arguing the effectiveness of UV but its use in a recirculating system which there is no data to backup your claim.

It does make a big difference if you are modeling bacteria or a parasite.

The article demonstrates UV is ineffective to control a water bound bacteria colony. You said this is irrelevant so it shouldn't count. And yet you will believe a parasite which spend the majority of its life cycle on the substrate or the host fish with a much smaller water bound window (roughy 48 hours) to have a significant impact on the theory?

Good night to all and enjoy the thread. Time to move on.

Sure. I think I have said what I need to say as well.

 

[nuclearheli]

Your conclusions are based on a quote you misinterpreted and I pointed that out to you. Not every single drop of water will pass the UV entering the sump. Similarly, not every drop of water will pass the UV from the sump entering your display either. If this is the set up you have then yes UV can be very effective controlling the spread.

Carbon is very effective as water purifier but if you use a single oz of it in a 4000g tank, I will argue it does nothing but not because the carbon suddenly lose the ability to absorb but because it's disproportionally inadequate. There are always more organic matters produced in a 4000g tank for a 1oz of carbon to absorb even assuming the carbon is never exhausted. I am not arguing the effectiveness of UV but its use in a recirculating system which there is no data to backup your claim.



The article demonstrates UV is ineffective to control a water bound bacteria colony. You said this is irrelevant so it shouldn't count. And yet you will believe a parasite which spend the majority of its life cycle on the substrate or the host fish with a much smaller water bound window (roughy 48 hours) to have a significant impact on the theory?



Sure. I think I have said what I need to say as well.

I did not misrepresent anything. If you are going to use references to research papers at least have the sense to buy and read them. The reality is you are wrong and I could care less. If you actually read the paper, and understood it, you would have nothing else to say.

 

[dzhuo]

The reality is you are wrong and I could care less.

Whatever you want to believe so suite yourself.

 

[dzfish17]

This is getting way more complicated than it needs to be. For any noobs that managed to read through all that garbage... UV will help against ich but it will not completely eliminate it. If you QT everything that goes into your tank you wont have anything to worry about.

I had to learn this the hard way last year. A local reefer was getting rid of his 6" passer angel and I was more than willing to take it off his hands, the only problem was that I already had fish in my QT tank so I took a chance. His tank looked healthy so I put the fish directly into the DT... 3 days later I had ich.

In most folks tanks you could just remove the fish to a hospital tank and treat them there but not in a 46" tall, 600g tank with a rockwall aquascape. I had no choice but to treat the entire tank with cupramine.

It killed the ich and I havent had an ich problem since but now Im sure I'll have copper leaching out of my rocks for who knows how long. Like I said, lesson learned... nothing goes in my tank without going through QT first.

 

[MrTuskfish]

This is getting way more complicated than it needs to be. For any noobs that managed to read through all that garbage... UV will help against ich but it will not completely eliminate it. If you QT everything that goes into your tank you wont have anything to worry about.

I had to learn this the hard way last year. A local reefer was getting rid of his 6" passer angel and I was more than willing to take it off his hands, the only problem was that I already had fish in my QT tank so I took a chance. His tank looked healthy so I put the fish directly into the DT... 3 days later I had ich.

In most folks tanks you could just remove the fish to a hospital tank and treat them there but not in a 46" tall, 600g tank with a rockwall aquascape. I had no choice but to treat the entire tank with cupramine.

It killed the ich and I havent had an ich problem since but now Im sure I'll have copper leaching out of my rocks for who knows how long. Like I said, lesson learned... nothing goes in my tank without going through QT first.

Good post and a good lesson!

 

[stevenw56]

Just read this thread and one thing comes to mind. Sure UV may not be 100% effective to eliminate ich, nor QT or garlic, hypo or the other methods. Instead of just using one method, why not use 2 or 3 or as many as possible to increase the percentages of eliminating the problem of ich.

 

[MrTuskfish]

Just read this thread and one thing comes to mind. Sure UV may not be 100% effective to eliminate ich, nor QT or garlic, hypo or the other methods. Instead of just using one method, why not use 2 or 3 or as many as possible to increase the percentages of eliminating the problem of ich.

Sure,UV might help ,a little. But ich doesn't even have to be in the DT. No ich, nothing for UV to kill. A solid QT regimen, using TT or copper on all new fish is as close to 100% as you can get. If ich is in the DT, sooner or later, its going to be a big problem. UV or no UV.

 

[tmz]

What do you think a typical aquarium uv does to organics if anything?

 

[tmz]

I did not misrepresent anything. If you are going to use references to research papers at least have the sense to buy and read them. The reality is you are wrong and I could care less. If you actually read the paper, and understood it, you would have nothing else to say.

Just to clear this up.
The paper talks about a multi tank system ,which would be a recircultating daisy chain type set up. Somehow ,you equate that to a single tank recirculating system running on a uv but you can't tell us what type or even the specifications of your uv or anything you may have gleaned from the paper . Yet we should take your word that a a paper which speaks about a single pass type setup actually means it is an effective in a recirculating system. Wow.

I think dzhuo did a fine job summarizing several relevant studies. There are more

But I agree with dzfish 17 ,enough is enough.

Quanrantine or at some point the tank will be fishless for 72 days with any survivors moved to qt for treatment. UV is mostly a waste of time for disease control in a recirculating system.

 

[MrTuskfish]

Sure, UV is great for ich from spreading between tanks; because every drop of water has to go through it. I admit to getting bored real quickly with scientific papers; but in a single home tank, I don't think you really need the science. Basic common sense tells me that every new ich theront can't find the UV intake before a new parasite finds a fish.
It seems that 3 issues are being discussed at once. 1.) UV helps "manage"ich for those who chose to live with it. I'm sure UV does help a little; but IMO & IME, "managing" ich, rather than eliminating it, will (almost) always come back. 2.) Eliminating ich from a single tank. IMO & IME, can't happen. 3.) UV as a barrier between tanks. Very common and effective. All of the ich must pass through the UV.