Is UV actually viable for parasite management?

[ReefTankENG]

I like UV to help keep things in check. Nothing gets eradicated. But helped keep an ich outbreak in check. I’ve see the occasional spots on my tangs for over a year with no issues… I assume it is because the UV keeps the population under control

 

[13rodo]

It's so hard to test to know if it helps at all, but I'm personally of the opinion that it doesn't help enough to justify the cost and setup etc.

That's because I ran fallow, had an eDNA test claim no cryptocaryon detected, introduced my fish that had been QT'd for 40+ days in copper and saw spots on a hippo tang within a week.

Ran another eDNA test, results said not detected, figured it was just hippos being goofy and introduced a clean hybrid powder tang only to see him break out with ich within 1 week (which then spread further to the hippo tang).

Pulled the two symptomatic fish, QT'd, then reintroduced 3 weeks later after another eDNA test claimed no ich again (which I knew was false because I didn't run fallow) and once again the hybrid powder tang developed symptoms within a week.

All this happened while running UV - maybe 57w isn't enough for my 220 total system volume, maybe it's because I had it plumbed on one of the dual returns.

I just know that - for me - I used to believe UV controlled ich and now I don't. My low grade presence should be the ideal candidate for UV to suppress.

The tank is fine now, I Just don't keep acantharus tangs in it. YMMV.

Ya I mean that was really the point of my post.

1) I was genuinely asking if I misunderstood the premise of the UV.
2) Assuming I didn’t misunderstand, UV isn’t ever meant to be a magic cure (if it does anything at all). From skimming it seemed like some think it’s magic.
3) If it doesn’t really control disease populations then it doesn’t really make much difference to the tank other than expense.

This last point was maybe a stretch. As @BeanAnimal pointed out, it likely does kill something. What the breakdown of that “something” is and whether it’s a net positive is anyone’s guess. My gut feel is that it’s probably a wash, but I can’t say for sure.

 

[allenk4]

The point is that enough theronts reach a fish and manage to attach to it to negate much of the value of a sidestream UV system.

In a scenario where the UV was plumbed into a closed loop under the display tank…is the "side stream" factor negated ?

If the UV unit is large enough to maintain the manufacturers suggested flow for addressing parasites, while passing 100% of the return flow thru the UV…does the discussion change?

The different portions of the discussion seems to have drifted from the OP’s question and fallen down into .1%, kill vs neuter, etc. Large companies, motivated by profit, do not invest in technology that does not have a good return on investment. From the information available to me, it seems that most of the commercial operations centered around marine fish use UV.

The COVID vaccine does t work every time, but we all took the Jab. UV may not work every time, but those who argue over the last .1% of water and give an example of a reef aquarium with stratified layers and uncirculated areas of water are just arguing for arguments sake and seem to be missing the point.

Just my opinion. I’m probably wrong.

 

[allenk4]

Context always matters, you are attempting false equivalency again.

A watt only tells us what is consumed, not what the lamp actually outputs. Consider ballast topology and lamp drive, lamp quality and spectrum, and the lamp’s age.

Now add those variables to the UV chamber volume and configuration, lamp dimensions, flow rate, dwell time, distance from the lamp, etc.

All of that goes into what the overall dose is. Read Jay's response regarding dose and dwell time and put it all together.

Engineered solutions vs hobby marketed, which Jay touched on as well.


That's a straw man supported by mocking. I said they aren't evenly distributed and they respond to light and host cues. Neither requires them to swim in a straight line. This was also clearly and contextually answered several times above. A uniform or ideal mixing model doesn't hold. Also see Jay”s post above, it further breaks your argument.

Each of your responses is another pivot from one fallacy derived argument to the next, ignoring the refutations already given by me, Randy, Jay and others.

Of all the logical arguments you have made so far; disputing that "a watt is a watt" is your least well founded.

Yes, many people understand that there is loss between input wattage and output. Usually as heat. Everyone knows a UV unit puts off heat, the smarter ones understand that’s power dissipation.

I suppose you are ignoring that manufacturers like Pentair publish the UV-C germicidal output wattage in their technical data and BRS does the same on the product page. You also seem to imply that these manufacturers don’t understand "aquarium conditions", whatever the hell that sweeping generalization is. They understand what UV-C dosage/exposure is required to neuter bacteria, algae and parasites. The flow rates are not pulled from thin air.

Those suggested flow rates are to damage the target in a single pass. Most reef systems are turning the system 4x per hour….almost 100x during the 24 hour pelagic stage of Ich.

99.9% of Dentists Agree…Brush your Teeth.

 

[allenk4]

Context always matters, you are attempting false equivalency again.

A watt only tells us what is consumed, not what the lamp actually outputs. Consider ballast topology and lamp drive, lamp quality and spectrum, and the lamp’s age.

Now add those variables to the UV chamber volume and configuration, lamp dimensions, flow rate, dwell time, distance from the lamp, etc.

All of that goes into what the overall dose is. Read Jay's response regarding dose and dwell time and put it all together.

Engineered solutions vs hobby marketed, which Jay touched on as well.


That's a straw man supported by mocking. I said they aren't evenly distributed and they respond to light and host cues. Neither requires them to swim in a straight line. This was also clearly and contextually answered several times above. A uniform or ideal mixing model doesn't hold. Also see Jay”s post above, it further breaks your argument.

Each of your responses is another pivot from one fallacy derived argument to the next, ignoring the refutations already given by me, Randy, Jay and others.

So, the difference between "hobby" grade and I guess ‘professional’ grade is how a piece of gear is "marketed" ? I’m surprised to hear you express that opinion.

 

[allenk4]

We also do not care or know if some fraction of ions like magnesium never pass through. They are evenly mixed.

Can these ions be both "evenly mixed" and "never pass through" ?

I suppose 99.9% leaves the word "never" in the discussion.

Someone will now argue that a Mg ion could indeed be sucked up by a coral, the instant it comes near and therefore never flow thru the pump. Maybe the number is actually 98.9% ?

 

[Randy Holmes-Farley Verified Community Expert]

Can these ions be both "evenly mixed" and "never pass through" ?

I suppose 99.9% leaves the word "never" in the discussion.

Someone will now argue that a Mg ion could indeed be sucked up by a coral, the instant it comes near and therefore never flow thru the pump. Maybe the number is actually 98.9% ?

Certainly something can be well mixed (meaning same concentration of ions everywhere) and not have every ion pass through any particular device. The numbers of individual ions and water molecules is beyond normal human comprehension, with 12,649,000,000,000,000,000,000,000 water molecules in 100 gallons. Statistically, plenty will not make it through a device for quite a while.

However, I think this is a curiosity side show more than a critical factor for whether a uv works.

 

[Privateye]

I just want to clarify a couple of minor things:

The Pentair comparison is a fallacy. Municipal water treatment and commercial/industrial food safety and a reef tank are not equivalent. The targets, required doses, sizing and flow configurations are all different. Hobby marketed vs engineered solutions.

It's not so much a food safety thing. Their biggest market for UVs is swimming pools, and the models offered for that industry are nearly identical to the aquaculture/aquarium UVs. They were adapted from the aquarium models. So in general, it's closer to apples to apples than you may think. Fresh water and different microbes of concern (e.g. brain-eating amoebae) of course, but food safety isn't really the industry you'd compare to.

A watt only tells us what is consumed, not what the lamp actually outputs. Consider ballast topology and lamp drive, lamp quality and spectrum, and the lamp’s age.

Actually, both are true. For instance, a 120 W Pentair UV lists an amp draw of 1.15 A at 120 V (I just went and checked). So the consumption is 138 W. Many manufacturers list their UV output in "μw sec/cm2" instead of mJ/cm2, so wattage is also used to measure lamp output. They're just different wattages.

 

[13rodo]

12,649,000,000,000,000,000,000,000 water molecules in 100 gallons. Statistically, plenty will not make it through a device for quite a while.

Big numbers are fun! It's kind of like discussing the Drake equation (or other variants). Statistically it's improbable that Earth is the only place with life given the size of the universe (Drake was only concerned with the galaxy, but the premise is the same). :)

 

[Randy Holmes-Farley Verified Community Expert]

Big numbers are fun! It's kind of like discussing the Drake equation (or other variants). Statistically it's improbable that Earth is the only place with life given the size of the universe (Drake was only concerned with the galaxy, but the premise is the same). :)

Yes, and in the context you mention, the huge numbers are critically important. A very, very, very rare event is still likely to happen somewhere. :)

 

[Jay Hemdal Verified Community Expert]

In a scenario where the UV was plumbed into a closed loop under the display tank…is the "side stream" factor negated ?

If the UV unit is large enough to maintain the manufacturers suggested flow for addressing parasites, while passing 100% of the return flow thru the UV…does the discussion change?

The different portions of the discussion seems to have drifted from the OP’s question and fallen down into .1%, kill vs neuter, etc. Large companies, motivated by profit, do not invest in technology that does not have a good return on investment. From the information available to me, it seems that most of the commercial operations centered around marine fish use UV.

The COVID vaccine does t work every time, but we all took the Jab. UV may not work every time, but those who argue over the last .1% of water and give an example of a reef aquarium with stratified layers and uncirculated areas of water are just arguing for arguments sake and seem to be missing the point.

Just my opinion. I’m probably wrong.

That scenario is still a side stream.

The case where UV gives complete control is when water moves from one tank to another with the UV (of proper size and flow rate) being in that line. Then, no control is seen in the first tank, but the disease propagule is kept out of the second tank. That’s how fisheries use them.

 

[Privateye]

I'm not sure that the "side stream" thing matters as much as people think. If the UV is properly sized and the flow rate is appropriate for the job, then over time it will still sterilize the microbes. I feel like if a side stream were an issue we'd see lots and lots of evidence of it over the past 30 years.

If you think about it though, the water in your tank is a side stream in itself. It's not always the oldest water that exits the tank first. There's a ton of mixing which means not all of it is processed within the same timeframe. The only exception would be a truly laminar flow tank.

 

[BeanAnimal]

These aren't clarifications. Both points are wrong. Let me address them.

I just want to clarify a couple of minor things:

It's not so much a food safety thing. Their biggest market for UVs is swimming pools, and the models offered for that industry are nearly identical to the aquaculture/aquarium UVs. They were adapted from the aquarium models. So in general, it's closer to apples to apples than you may think. Fresh water and different microbes of concern (e.g. brain-eating amoebae) of course, but food safety isn't really the industry you'd compare to.

Food safety was an example of an engineered application. Market share was not relevant.

Where it matters for life safety, vs "polishing", pool systems are validated against published standards for named organisms, and tested in the validated reactor configuration at rated flow. The reactor being the specific UV unit, flow rate, and other applicable parameters.

That is the "apples to oranges" in context to "hobby grade" vs a commercially engineered and validated solution.

So, engineered commercial solutions that are required to pass validation for the applicable installation or standard for the organisms in question, not marketing sheet sized units aimed at hobby or personal use or "water polishing" type applications.

The only thing "apples to apples" is water and UV. Jay posted the doe rate for the organisms in question here, and gave clear added context as to why Allen's overall argument is broken one way or the other. That is where this sits.

Actually, both are true. For instance, a 120 W Pentair UV lists an amp draw of 1.15 A at 120 V (I just went and checked). So the consumption is 138 W. Many manufacturers list their UV output in "μw sec/cm2" instead of mJ/cm2, so wattage is also used to measure lamp output. They're just different wattages.

You're defending Allen's equivalence fallacy while making my point. If the word carries two different quantities, consumption and output, then "a watt is a watt" is wrong for the implied meaning. That was the clear point I made.

Input wattage, even if directly measured, does not tell us lamp output, for all of the reasons listed above, and it tells us nothing about your second point, which is entirely wrong.

"μW·s/cm²" is not the wattage that you imply at all. It can't be deduced from power consumption, and is not a direct measure of the lamp's output. It is dose.

But let's be more clear, it as a W init to denote energy delivered. That is a function of the lamp, in that specific chamber, with its specific quartz sleeves, average distance from the lamp, flow patterns, and dwell time at a rated flow. The "watts" in the unit are part of the irradiance term at the specified target wavelength that is delivered in the dose with all of those other factors added in, not electrical input or the lamp's total output.

https://www.epa.gov/system/files/documents/2022-10/ultraviolet-disinfection-guidance-manual-2006.pdf

 

[Jay Hemdal Verified Community Expert]

I'm not sure that the "side stream" thing matters as much as people think. If the UV is properly sized and the flow rate is appropriate for the job, then over time it will still sterilize the microbes. I feel like if a side stream were an issue we'd see lots and lots of evidence of it over the past 30 years.

If you think about it though, the water in your tank is a side stream in itself. It's not always the oldest water that exits the tank first. There's a ton of mixing which means not all of it is processed within the same timeframe. The only exception would be a truly laminar flow tank.

It’s a huge thing. The dwell time, as I’ve said means the fish are infected with enough theronts to build the infection because enough of those dont pass through the sterilizer.

Noga and other primary references all say that aside from underpowered units, it is the primary reason why UV does not control protozoan epizootics in aquariums.

 

[BeanAnimal]

I'm not sure that the "side stream" thing matters as much as people think. If the UV is properly sized and the flow rate is appropriate for the job, then over time it will still sterilize the microbes. I feel like if a side stream were an issue we'd see lots and lots of evidence of it over the past 30 years.

If you think about it though, the water in your tank is a side stream in itself. It's not always the oldest water that exits the tank first. There's a ton of mixing which means not all of it is processed within the same timeframe. The only exception would be a truly laminar flow tank.

You just torpedoed Allen's argument and your own in the same post. Proper size doesn't address the organisms that don't make it there to begin with. The whole "mixing" thing that has been settled here repeatedly for three pages.

Jay also answered and explained why the semantics of where the water goes and returns does not change the "side stream" designation if the water is being returned to the tank.

It is only not a side stream when all of the water passes through the unit and does not return, tank A to filter to tank B. That is the only case where the unit can be properly sized against a known volume at a known flow, because every organism in that water makes it through the properly sized filter.

 

[Privateye]

It’s a huge thing. The dwell time, as I’ve said means the fish are infected with enough theronts to build the infection because enough of those dont pass through the sterilizer.

Noga and other primary references all say that aside from underpowered units, it is the primary reason why UV does not control protozoan epizootics in aquariums.

I'd be happy to read a reference or two on it (I have Noga's book if it's in there) if you have the time to point me towards them, but the point I was trying to make is not that the side stream effect isn't important, but that it already happens within the tank. That makes it hard for me to imagine a way to even quantify the effects of some of the flow bypassing the UV and attribute the problem to the UV bypass. Perhaps there's a study that directly compared the two on a recirculating system that I haven't seen. I just think when you consider all of our different combinations of pumps, tanks, plumbing, powerhead directions, etc...it's hard to point the finger at a UV bypass for me. Continued below though, linearly...

The whole "mixing" thing that has been settled here repeatedly for three pages.

This part is pretty true, although it appeared on the most-recent page I saw, and that explains the misunderstanding. I totally posted in this thread long ago, saw it show up on my feed when I had 10 spare minutes, read the latest page and the one before it, and said tl;dr to the rest. I've gone back now though. You spent pages (and perhaps hours) agreeing with my point. I was reading side-stream as simply a bypass on the UV, which is something many of us use to control flow to the unit without impeding total system flow. My error. The effect happening in the tank was my point, so I think I just miscommunicated what I was talking about. While I saw "side-stream" as a UV bypass, others were triggered from prior conversations where it was used differently. Lmk if I'm misinterpreting the situation.

Food safety was an example of an engineered application. Market share was not relevant.

Where it matters for life safety, vs "polishing", pool systems are validated against published standards for named organisms, and tested in the validated reactor configuration at rated flow. The reactor being the specific UV unit, flow rate, and other applicable parameters.

That is the "apples to oranges" in context to "hobby grade" vs a commercially engineered and validated solution.

So, engineered commercial solutions that are required to pass validation for the applicable installation or standard for the organisms in question, not marketing sheet sized units aimed at hobby or personal use or "water polishing" type applications.

The only thing "apples to apples" is water and UV. Jay posted the doe rate for the organisms in question here, and gave clear added context as to why Allen's overall argument is broken one way or the other. That is where this sits.

This part is a little different though. Polishing isn't the only goal on pools - there are pathogenic microbes in that water that need to be addressed (e.g. E. coli from dirty butts, which has published standards and the UVs are tested for it). They can't say that you can lower your chlorine concentration by using this product without such testing, of course. So when I initially read your justification for how they're different, it sounded like "they're the same. They both check all of the boxes."

Both Pentair versions sport the same performance characteristics as I recall. Both are also sold for freshwater applications to target microbes that overlap both fish and pool industries. Microbes that have published data, and when necessary (hey, that's business) they are tested for.

You're defending Allen's equivalence fallacy while making my point. If the word carries two different quantities, consumption and output, then "a watt is a watt" is wrong for the implied meaning. That was the clear point I made.

Input wattage, even if directly measured, does not tell us lamp output, for all of the reasons listed above, and it tells us nothing about your second point, which is entirely wrong.

"μW·s/cm²" is not the wattage that you imply at all. It can't be deduced from power consumption, and is not a direct measure of the lamp's output. It is dose.

But let's be more clear, it as a W init to denote energy delivered. That is a function of the lamp, in that specific chamber, with its specific quartz sleeves, average distance from the lamp, flow patterns, and dwell time at a rated flow. The "watts" in the unit are part of the irradiance term at the specified target wavelength that is delivered in the dose with all of those other factors added in, not electrical input or the lamp's total output.

This part has me confused, but I think I was just unclear again because I didn't check the long history (again) but my point was that all of these are read in Watts, so Watts can be used to express these values, but they are different numbers. I even posted an example. So I think we may be in agreement on this too. I will take responsibility for not reading enough of the prior context, but when it comes to assuming that I'm defending the idea that all of the Wattages are the same just because I quoted your post, then maybe you attributed my thoughts to a prior argument instead of looking at what I was posting numbers for. I went after the whole "A watt only tells us what is consumed, not what the lamp actually outputs" part of your quote. I didn't say that input Wattage tells us the output - I said the opposite. Wattage can tell you multiple things, but you can't derive one Wattage from another, right?

Are we friends now? Lol.

 

[rtparty]

The COVID vaccine does t work every time, but we all took the Jab.

Did “we” all take it? Does it even “work” some of the time? Science, very loose term when it comes to the jab, has no clue what it actually does and doesn’t do.

Science does have a good understanding of what UVC does though.

Whether the science stands up for some in here is irrelevant to me and likely most hobbyists. Some very large and well known breeders will tell you how much healthier their fish are when it’s in use. The science of why makes no difference.

Kind of like Prime and whether or not it works. The scientists on here will tell you it can’t and doesn’t work. Those ACTUALLY using will tell you it saves lives of millions of fish and you can clearly see it work. The largest fish breeders in the world use it routinely to save fish. But the scientists with no real world application will sit and argue about how “it can’t work.”

It really is a giant waste of time to go back and forth with a few users on here. Multiple are in this thread

 

[RobertK]

I’ve successfully used UV twice to deal with Ostreopsis and neither time did I plumb it into the display tank. It’s amazing how quickly it slows and eradicates them

Can I ask what type of UV unit (and on what size tank) you used for that and how it was plumbed?

I know the OP started this thread to ask about using UV to prevent parasitic infections in powder blue tangs, but it has already gone so far astray that perhaps it is OK to discuss what other things UV might work well for?

 

[rtparty]

Can I ask what type of UV unit (and on what size tank) you used for that and how it was plumbed?

I know the OP started this thread to ask about using UV to prevent parasitic infections in powder blue tangs, but it has already gone so far astray that perhaps it is OK to discuss what other things UV might work well for?

25w Aqua UV on a 120g plus 40b sump and NYOS440 which is like 110ish gallons. Both times it pulled water from the sump and dumped it right back into the sump. Knocks out Ostreopsis in days

No idea the flow rate. Just some DC Jebao pump not turned up crazy high. Maybe 150-200gph? Total guess

 

[allenk4]

Certainly something can be well mixed (meaning same concentration of ions everywhere) and not have every ion pass through any particular device. The numbers of individual ions and water molecules is beyond normal human comprehension, with 12,649,000,000,000,000,000,000,000 water molecules in 100 gallons. Statistically, plenty will not make it through a device for quite a while.

However, I think this is a curiosity side show more than a critical factor for whether a uv works.

How can it be "beyond normal human comprehension" and then you express it right after the comma ?