[spn1025]

I'm currently running a Green Killing Machine UV sterilizer in my cichlid tank. Keeps the water crystal clear.

Just crossed my mind, so figured I'd ask, is there any harm or anything negative with running a UV sterilizer non-stop?
I know it kills a lot of harmful parasites/bacteria, but what about good bacteria? It obviously kills the good stuff as well. So that would mean more gravel vacuums since waste isn't breaking down. The fish are all healthy, so no negative effects on the fish themselves.

Anyone see an issue with constantly running one?

 

[spn1025]

Basically, should I be running this constantly or should I only be running it when needed (bacterial bloom, algae outbreak, etc)

 

[DJRansome]

I don't think it hurts, but I have never seen the need for one personally. I have never had a bacterial bloom or algae outbreak (at least in the water column). My water is crystal clear naturally.

 

[ironspider]

My water is crystal clear with just weekly water changes, never considered a uv.

 

[nycman]

i run them on all my tanks - saltwater reef, freshwater planted, and Mbuna. Keeps water crystal clear and no fish diseases. But who knows how much UV is contributing given all the parameters. Agree that good old water changes are far and away the most significant method of keeping your water clean, clear, and nitrate free. You learn this when keeping 3-5 gallon fish bowls, which I do along side my very large tank aquarium hobby. I have 5 gallon comet bowl where i do 100% water change 1-2x per week with old Mbuna tank water, and a 3 gallon white cloud minnow bowl where I do same with old freshwater planted tank water. Both bowls have no filtration, no airstones, nothing. And fish are not only thriving after 2 years, but breeding.

 

[Mcdaphnia]

UV is critical if you have a centralized filter since parasites and bad bacteria and green water can be shared otherwise. The good bacteria that we call the cycle stick to surfaces, so they don't go through the UV. Green water is actually a first food for hatchlings of fish species with very small eggs, but being cichlid keepers we don't run into that.