Loaches Online Forum

Hi Mikev,

With UV, one specific danger is uncycling the tank. I had two serious episodes like this, in both UV fully eliminated the nitrite processing bacteria. In one case, I had to fully empty and wash the tank before I could restart the cycle.

okay now I'm really confused. Isn't almost all of the benifcial bacteria in the substrate and filter (my UV unit is after the filter)? I was under the impression that the amount of bacteria in the water itself is pretty small.


Batch

Generally, what you said is true.

However,

1. This is often not true in new tanks, this is why UV is not supposed to be run in the first 3 months of tank life. While I have a way of dealing with this (the unsafe period depends on how you started the tank), this makes using UV on qtanks which tend to be young even more dangerous. And of course, UV is of most use on qtanks because this is where diseases are more common....with proper quarantine procedures there should be almost no disease in permanent tanks, and thus no UV need.

2. There are indirect ways UV can wipe out the bacteria entirely even in the substrate and filter(s) even in a fully mature tank. This was my second accident. (Yes, I do know how it did it...this can be prevented, but there likely are other ways UV can wipe out the tank.)

Hi Batch,

This previous discussion might be of help: http://forums.loaches.com/viewtopic.php?t=4281

Emma