What do people think of UV filters for bacteria, parasite, and algae control I do not have an algame problem because of frequent water changes and excellent nutrient balance. However one cannot predict the onset of harmful pathogens. Any favorite brands? Thanks.
This is a great topic! There is a shocking amount of bad information out there on UV sterilizers in FW. They are a frequently used tool on the salty side though, and their effectiveness in FW is well research for human safety standards on fresh drinking water. In short, properly used they are highly effective at what they do.
So, what do they do? They can kill microbial life as it flows through the illuminated chamber. What don't they do? They can't kill complex, larger organisms, even if they flow through the chamber. Nor will they impact anything that doesn't flow through the chamber. So, they won't take out your BBA or green spot algae (though it's possible they will stop them from spreading...), and they won't be a danger to your population of pods (if you keep your tanks that way).
In practice, they are very effective at breaking the infection cycle of many pathogens aand parasites of aquatic life (think spreading bacterial infections, ich, etc.). Those organisms typically have a free swimming/drifting stage which allows them to spread from one host to the next. It is this stage that UV can effectively disrupt. Once a fish is infected though, it won't cure it. But it can stem an outbreak before it happens. They can also help with pelagic microalgae and some forms of cyanobacteria. Additionally, they are dramatically more effective in FW than in SW, which is funny when you think about how often they are used in reef systems, and how little in FW hobby. (Just compare the ratings for any units, it's almost comical.)
I pretty well only use mine on my QT tank. I have just one QT tank, and I like to break it down between uses where possible, especially when I am shifting between using it for SW and FW. So, I have a hang-on UV sterilizer for when I bring in new fish. It allows me to help prevent outbreaks of disease on groups of fish while they are stressed and most susceptible. Because it is a hang-on rather than a hard plumbed unit, I can also quickly add it to a display tank if something seems amiss where UV would help (though I've thankfully not had to do so yet). Bulbs are expensive, so I also like that I am not running it all the time. This one works by attaching a small pump (stay within the gph rating to ensure it is effective!) in the tank, which pumps the water through the chamber and then returns it right back into the tank using a spout that is also the hanger. Sets up and breaks down in minutes. Highly recommend!
