Myth or Fact?

[jamjarjames]

Hi

Ive heard two sides to the following story so hopefully this poll should clear things up a little.

Some gu at a garden centre said that UV Sterilisers will kill all the bacteria off in the tank and the filter and so Ammonia and Nitrite will just keep going up and up and up untill your fish die. Yet my LFS said that a UV steriliser will kill of bacteria that passes through the UV but not bacteria that is already present in the filter. So cast your vote

 

[mogurnda]

Total myth. The UV will only kill suspended bacteria, the ones you care about live as a biofilm on surfaces.

 

[RobUK]

Yep
As a UV sterlizer only sterlizes what passes directly under the UV light
If your looking for it to clear up algae then they are amzing for it, we have one built into to the external filter box of our pond and it really does desimate the algae

 

[Macromatt]

grrr..misread the question....clicked yes..oops...

UV only kills what goes through it. Not what is in the rest of the tank.

Matt

 

[jacblades]

such a disappointment does that mean it will or wont kill your beneficial bacteria?

 

[Leopardess]

It will NOT harm your beneficial bacteria.

 

[fishypoo2]

UV sterilizer only kills suspended organisms when passing under the light, not beneficial bacteria, which stays in the filter, etc.

The poll dosen't make much sense, you gave two exmples and said yes or no.

 

[Leopardess]

Read above where it says Yes & No. It says:

"Do UV's kill off Bacteria in the filter?"

 

[redpaulhus]

Agreed - It won't kill whats in the filter - but I wouldn't run the UV during the cycling process, when you want any beneficial bacteria to live until they have found the filter media... especially since many people put the UV "upstream" from the biomedia - so how are the bacteria supposed to get there ?

I worked at a store about 15 years ago, we were cycling a new 60 foot section of CA Aquarium LFS tanks - picture 60 feet of connected acrylic (same maker as Seaclear) tanks with a wet/dry the size of a clothes washer and dryer... now picture two 36" UV tubes... now picture about 4 gallons of Fritz Zyme #7 (one per week) that we poured into the system. We were trying to stock lightly but the owners of the chain wanted to see fish ASAP... A month later the water tests are still showing ammonia, zero nitrite, zero nitrate WTF ?

:idea2: Then it hits me -- we never turned off the UV's. Bang -- the system hard cycles, within two weeks ammonia was zero, in a month it was cycled... many danios, tetras, and platys gave their lives for that mistake...

 

[JSchmidt]

Another explanation might be that Fritz Zyme doesn't contain nitrifying bacteria of the correct variety...

Jim