Personally, I am not a fan of uv
sterilizers in general. My thoughts on the topic are that they are indiscriminate killers. Sure they'll take out some free floating micro algae. But they'll kill anything that passes through them, including microorganisms that are beneficial.
I may get flamed for this, but I've always considered them a lazy approach to water quality. Like, even lazier than my approach. I use a large refugium full of algae and pods
to uptake extra nutrients. Barring an unexpected death in my tank, algae growth in the main tank is minimal. I also have a few filter feeders that would starve if I used uv
Parasites such as ich shouldn't be introduced with proper quarantine. But accidents happen. To eradicate ich using a uv
sterilizer is rather difficult though. Not only does wattage and gph
have to be precisely calculated and matched to do any good at all, ich is only free swimming for a fraction of its life. From a strictly mathematical perspective, it is possible to have a properly set up uv
sterilizer run indefinitely without eradicating ich. Especially in larger tanks.
Essentially, I do a cost/benefit analysis and all I really see is power consumption and dead microfauna/microflora with no tangible benefits. I know many will disagree with me, this is simply how I see the topic.