UV... any down sides???

[Magnum Man]

so back when I was into fish 15 years ago... there really wasn't UV for Aquariums ( that I remember ) so I have no experience with them in the aquarium setting... I get that there are a couple things they are promoted for... but are there negatives as well... kills beneficial bacteria as well??? any negative effects on plants, if it's capable of destroying some algae???

Thanks

 

[CaptainBarnicles]

From my understanding, they're only good for destroying what's in the water column...so BB will be fine. Green water algae and nasty pathogens that might be lurking in the water would be done away with. I considered one a little while a go but I realised it's a lot of money for nothing when keeping up with big regular water changes can keep on top of those things anyway so I guess it's each to their own?

 

[Magnum Man]

I know my Tilapia Fingerling Supplier recommends them, probably because of the Biomass a lot of systems are running, & they are being raised for food... my aquariums all sitting for 15 years dry, but with all the gravel & equipment inside, even though I fully empty them & vacuumed them out with a shop vac, I did not disinfect anything, before refilling them... in fact I got in a hurry with the 2nd tank, & added water, then siphoned it out & tried to shop vac as best I could wet... I thought maybe one hang on tank or canister filter I could move around if needed might be a good idea... then started wondering if there are negatives they just aren't mentioning

 

[Wills]

I don't know of any downsides, but most people think they are belt and braces, over-the-top territory. They are often expensive within an already expensive hobby so again not that popular. They often tie into some kind of external filtration or usually sumps so click into some of the higher ticket corners of the hobby.

For me on a bigger tank (55 gallons +) I'd personally like to be able to run one but I appreciate they are not for everyone.

 

[Magnum Man]

"belt and braces" been a long time since I heard that saying... don't know you, but I like you already Wills...

 

[Boundava]

Sis had a bad infestation of algae in her 40 breeder and so we thought that if we put a UV light in the Tidal filter, which is black plastic, that we could help eliminate the algae issue. The next day a vast majority of the fish in the tank were dead. I'm not sure if it's related but we quickly removed the UV sterilizer and returned it. sis was devastated as a lot of expensive fish were on the tank but you live and learn. I guess. I would not do UV again

 

[CaptainBarnicles]

Sis had a bad infestation of algae in her 40 breeder and so we thought that if we put a UV light in the Tidal filter, which is black plastic, that we could help eliminate the algae issue. The next day a vast majority of the fish in the tank were dead. I'm not sure if it's related but we quickly removed the UV sterilizer and returned it. sis was devastated as a lot of expensive fish were on the tank but you live and learn. I guess. I would not do UV again

That sucks if it was related

 

[Wills]

Sis had a bad infestation of algae in her 40 breeder and so we thought that if we put a UV light in the Tidal filter, which is black plastic, that we could help eliminate the algae issue. The next day a vast majority of the fish in the tank were dead. I'm not sure if it's related but we quickly removed the UV sterilizer and returned it. sis was devastated as a lot of expensive fish were on the tank but you live and learn. I guess. I would not do UV again

Wow, that's rough! When you say you added a UV light into the filter, was it one designed to be submerged? Was it an aquarium-specific product?

Surely UV effect on fish would be something to lead to long-term health problems like UV exposure in humans? Not something over night?

Wills

 

[Byron]

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.

 

[BrianK]

I have a cheap UV light in my filters. I originally got one because of a stubborn bacterial bloom that would not go away no matter what I did. The UV light took care of it in one day. After that I just kept it going a few hours per day. No particular reason.

 

[Boundava]

Yeah, everyone was healthy the night before. The UV was the only new addition to the tank, so logically we couldn't think of anything else that would have caused multiple fish to die overnight.

 

[Boundava]

Wow, that's rough! When you say you added a UV light into the filter, was it one designed to be submerged? Was it an aquarium-specific product?

Surely UV effect on fish would be something to lead to long-term health problems like UV exposure in humans? Not something over night?

Wills

I'm not sure. like I said, a bit too coincidental for me. Gobies, hillstream loaches, school of danios and a pleco. Thriving and then dead after adding UV to tank. The last three gobies were not doing well but slowly came back. You can see them in the 40 breeder in the video I just uploaded in my journal on the slimmed down fish room. Sis wound up moving inhabitants from her 75 acrylic as she didn't want the 40 as a river tank any longer.

 

[Wills]

I'm not sure. like I said, a bit too coincidental for me. Gobies, hillstream loaches, school of danios and a pleco. Thriving and then dead after adding UV to tank. The last three gobies were not doing well but slowly came back. You can see them in the 40 breeder in the video I just uploaded in my journal on the slimmed down fish room. Sis wound up moving inhabitants from her 75 acrylic as she didn't want the 40 as a river tank any longer.

The reason I asked is because a more likely scenario is that it wasn’t a suitable fitting for an aquarium and it released voltage into the water. I’ve not heard of Tidals having a UV attached?

 

[Endlersendlers]

Hi, I use UV in my tilapia pond, 36 gal community tank, and in a 5 gal betta tank. It kills the algae in the water and effectiveness depends on flow rate and strength of the UV. I agree that the UV suspected to have killed the fish probably electrocuted them for one reason or another (not submersible, defective or damaged wiring) or maybe they died from a problem the UV was purchased to solve. Carcinogenic? The water it is used in is not carcinogenic but UV light is bad for cells and your eyes and that is why it should not be looked at when it is on or exposed to living organisms you like. Unfortunately, these little IV bulbs are available online for aquarium use without explanation that they should only be used in an enclosed area like a filter and not in line of sight to the fish, people, or pets. I watch for UL listed or another such designation (is it EBL?) to show that it’s been tested for electrical safety and passed. When COVID was running rampant I felt a little better that my tank probably was not a breeding ground for the virus. My fish have not, knock on wood, had any diseases or infections, bacterial or fungal, since I got back in the hobby. My only casualties have been the occasional jumper and physical accidents (such as getting caught in the skimmer) and once forgetting chloramine treatment for an hour. I am also pretty disciplined about weekly to twice weekly water changes, unlike my college days. I really like the UV lights but understand people have survived without them just fine except maybe with greener water.

 

[Endlersendlers]

Hi, I use UV in my tilapia pond, 36 gal community tank, and in a 5 gal betta tank. It kills the algae in the water and effectiveness depends on flow rate and strength of the UV. I agree that the UV suspected to have killed the fish probably electrocuted them for one reason or another (not submersible, defective or damaged wiring) or maybe they died from a problem the UV was purchased to solve. Carcinogenic? The water it is used in is not carcinogenic but UV light is bad for cells and your eyes and that is why it should not be looked at when it is on or exposed to living organisms you like. Unfortunately, these little IV bulbs are available online for aquarium use without explanation that they should only be used in an enclosed area like a filter and not in line of sight to the fish, people, or pets. I watch for UL listed or another such designation (is it EBL?) to show that it’s been tested for electrical safety and passed. When COVID was running rampant I felt a little better that my tank probably was not a breeding ground for the virus. My fish have not, knock on wood, had any diseases or infections, bacterial or fungal, since I got back in the hobby. My only casualties have been the occasional jumper and physical accidents (such as getting caught in the skimmer) and once forgetting chloramine treatment for an hour. I am also pretty disciplined about weekly to twice weekly water changes, unlike my college days. I really like the UV lights but understand people have survived without them just fine except maybe with greener water.

I am going to amend that - I’ve seen Boundava’s videos and he is meticulous with his tanks. I don’t think there was a preexisting problem that killed his fish. Much more likely he got a defective device and I don’t blame him for not wanting to risk it again in his beautiful communities. As a nurse I appreciate the germ killing aspect but there’s no big wow factor before and after.