UV sterilizers are not effective and we should all stop using them, Right?

Daniel76 · Jan 24, 2020

Plenty of anecdotal stories saying they are great, but limited scientific articles.

Can anyone provide something other than this article which states:

"mortality rates among exhibit fishes at a public aquarium were unchanged by installation of a UV sterilizer that lowered the total bacteria at the contact site by 98 %."

happysalt · Jan 24, 2020

I have found them very effective at killing bacterial blooms. i'm sure if you looked at it and said killing a bacterial bloom reduces the bacteria in the water which is using up oxygen that otherwise would be available to the fish, then it would probably be a positive thing for every living creature in the tank right?

homer1475 · Jan 24, 2020

Worked for me to rid my tank of Dino's.

AZMSGT · Jan 24, 2020

You do you, Me, I'm going to keep using my UV. I believe it has been a major part of keeping dinos out of my low nutrient tank.

hart24601 · Jan 24, 2020

I have eliminated dino with them on several systems. It's been clear and dramatic overnight improvements but you're right it's not scientific.

I don't suspect research published will focus on systems of our small size, in general, and items like dino reduction since it's not all that relevant to large Aquaculture.

So it really depends on what the hobbyist is hoping to accomplish with UV of how one can interpret that study - and of course the study can't be taken as definitive unless the UV intensity, flow, and turnover match your system.

mrpizzaface · Jan 24, 2020

Daniel76 said:
Plenty of anecdotal stories saying they are great, but limited scientific articles.

Can anyone provide something other than this article which states:

"mortality rates among exhibit fishes at a public aquarium were unchanged by installation of a UV sterilizer that lowered the total bacteria at the contact site by 98 %."

Can you link the article?

hart24601 · Jan 24, 2020

mrpizzaface said:
Can you link the article?

I think this is the article in question from 1981.

https://www.int-res.com/articles/meps/6/m006p295.pdf

Deep dive coral · Jan 24, 2020

The technology has come so far since 1981... I probably wouldn't go by that.

ScottR · Jan 24, 2020

hart24601 said:
I have eliminated dino with them on several systems. It's been clear and dramatic overnight improvements but you're right it's not scientific.

I don't suspect research published will focus on systems of our small size, in general, and items like dino reduction since it's not all that relevant to large Aquaculture.

So it really depends on what the hobbyist is hoping to accomplish with UV of how one can interpret that study - and of course the study can't be taken as definitive unless the UV intensity, flow, and turnover match your system.

Of course this is anecdotal and there aren’t that many scientific papers on reef tanks, let alone dinos. With that said, UV filters have helped to defeat lots of tanks with dinos. If it’s worked for you and countless others, I’d trust it. One would need to make sure that they get the proper rated UV and the right amount of flow. I’ve seen UV filters take care of bacterial blooms numerous times.

Daniel76 · Jan 24, 2020

captrichc said:
The technology has come so far since 1981... I probably wouldn't go by that.

Feel free to link a scholarly peer reviewed article that says something different.

If you don't like peer reviewed scholarly articles, try this one from marine depot in 2017 : https://www.google.com.au/amp/s/blo...ut-uv-sterilizers-and-reef-aquariums.html/amp

Daniel76 · Jan 24, 2020

ScottR said:
Of course this is anecdotal and there aren’t that many scientific papers on reef tanks, let alone dinos. With that said, UV filters have helped to defeat lots of tanks with dinos. If it’s worked for you and countless others, I’d trust it. One would need to make sure that they get the proper rated UV and the right amount of flow. I’ve seen UV filters take care of bacterial blooms numerous times.

What "has worked" for someone?

ScottR · Jan 24, 2020

Daniel76 said:
What "has worked" for someone?

UV in defeating dinos. I see around 50 tanks a week. A tank can go months with dinos, throw a UV on and you can see the numbers decline.

Daniel76 · Jan 24, 2020

happysalt said:
I have found them very effective at killing bacterial blooms. i'm sure if you looked at it and said killing a bacterial bloom reduces the bacteria in the water which is using up oxygen that otherwise would be available to the fish, then it would probably be a positive thing for every living creature in the tank right?

Sure, possibly, but is that why we are buying them? To up O2 count?

Daniel76 · Jan 24, 2020

ScottR said:
UV in defeating dinos. I see around 50 tanks a week. A tank can go months with dinos, throw a UV on and you can see the numbers decline.

But can / should we assume that it defeated them and not something else?

Gareth elliott · Jan 24, 2020

UV c does kill microbes and macro life. But the effect on a particular life form is heavily dependent on the amount of protection that life form has, and the exposure time to the UV light. I have a 55w uv bulb on an outside 1000 gallon pond. Has great effect on suspended green algae, have seen no effect on parasitic copepod reproduction or fw black ich. Bacterial infections are very dependent on the host animals immune system and overall health. While anecdotal this system has been running for 17 years come this summer.
I think implementation of UV must have realistic goals. My goals with uv have to do with algae, not fish pathogens. If your goal is reduced infections it maybe beneficial as part of a wholistic approach. Where maintaining fish health is your primary process and properly sized and applicable flow rate uv is merely secondary.

UVC in air on surfaces require approximately 30 minutes of contact to disinfect bacteria. While not a direct analogy for water borne organisms, does provide a starting point on why they are used in waste water sterilization. In this application the size has flow rates are carefully managed. As a single ecoli cell is enough to make someone ill. Most bacterium that number is in the millions.

ScottR · Jan 24, 2020

Daniel76 said:
But can / should we assume that it defeated them and not something else?

Good question. One would think so.

Daniel76 · Jan 24, 2020

ScottR said:
Good question. One would think so.

What I will say: Maybe we would apply some robust scientific methodologies to this?
What I want to say: That statement is wrong.

hart24601 · Jan 24, 2020

Daniel76 said:
But can / should we assume that it defeated them and not something else?

In my cases yes, easily. I would suggest searching around the site more. Without exaggeration I have seen improvement overnight on dinos on multiple systems. This of course depends on the species of dinos as well with species that dissolve into the water column at night being the most easily impacted, but in my time reefing there are few if any things I have observed that made such a fast and obviously change.

The real debate over UV in our systems seems to be over fish parasites and their usefulness in that capacity. Their benifit for clearing some species of dinos has been evidenced dozens of not hundreds of times now. In many cases such as myself, with 0 other treatments done at the same time.