UV sterilizer light and beneficial bacteria

[aquablizz]

I have been running a UV light for approx. 6 months.. Does this have an effect on beneficial bacteria??

Probably a dumb question but I'm throwing it out there..

Blizz

 

[fab]

Probably a dumb question but...

No such thing...only answers can be dumb, particularly when they are incorrect or mean spirited or made by politicians.

Running uninhabited water through a UV sterilizer has no effect other than wasting electricity and UV bulb life. There is no effect on the water, itself, other than the transfer of a tiny amount of heat. You could heat your tanks this way, but it would be about as effective as rubbing sticks together underwater. The point is there is no germicidal effect on water. When the water returns to the tank from the UV sterilizer it is just the same ole water that it was before its side trip.

Germicidal UV radiation does not affect water. It only affects critters that inhabit the water, if and when they pass through the UV sterilizer. Beneficial bacteria do not live in the water column. They live on surfaces of things such as rock, sand, glass, filtration media, etc.

Does this have an effect on beneficial bacteria??

Not really...Well, yes actually, if they happen to caught up in the water column for some reason, they could be swept up and radiated. But that is not where they spend time. If any beneficial bacteria do get radiated it would be a miniscule percentage of their population in your tank.

Furthermore, UV does not directly kill critters. It mucks with their DNA, gelding them, so to speak. The very few beneficial bacteria that may get radiated will be flushed from the UV sterilizer back into the tank to live out their happy little beneficial lives, but as eunuchs, and only if they are affected.

Not all critters are vulnerable to UV, particularly ones that are covered by or encased in protective gear...hard casings, shells. They sort of keep their DNA in the shade and get a free pass on the UV ride.
fab

 

[aquablizz]

thanks for you reply FAB... as of now I am a fish only person but until I have things figured out, I don't want to take the next step... Have had a 75 gal. fish only display tank for 25 years. I am envious of all the beautiful reef tanks that I see on this site but for every beautiful tank post it seems there are 1000 problems post.. I want to be able to enjoy the hobby and not have it too labor intensive... It appears that an impossibility if I want to start playing with coral and inverts.
Thanks again for the reply.
blizz

 

[fab]

I hope my post helps you sort out at least one aspect of your concerns.

Also, keep in mind that most people do not post about problems unless they have a problem. Many people who are not having problems may not post at all. A lot of folks post just to learn or to share knowledge.

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, the answer to your question depends on what you think are beneficial bacterial. Nitrogen cycle bacteria won't be killed because they are mostly on surfaces.

But other bacteria that may feed filter feeders will be killed.

 

[fab]

But other bacteria that may feed filter feeders will be killed.

Good catch. Thanks Randy.
fab