I guess I wouldn't use the word need, but UV is another tool available to us as a "holistic" approach. QT is not eradication; I would imagine eradication would require a massive amount of money and protocol that I couldn't achieve. UV is also not eradication, but they do reduce the free floating population that has the potential to overwhelm closed systems.
I QT and dose meds regardless of seeing any disease and have had a few things slip through that quickly went severe. What I found interesting was the tank running UV showed no signs versus the tanks without UV. UV definitely reduces free floating algae and bacterial blooms and clears water so well and these alone, for me at least, validates UV use.
I watch BRStv and I don't believe these guys do all the testing they do just to boost sales. I believe they actually just want to know if certain products work and are worth the expense. They are convinced UV is worth it, maybe I'm a sucker though

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