Is there a need for a quarantine tank...?

I have both, but with the sterilizer you will not kill everything. I only use mine when I start having an algae bloom or run it for 12 hours after doing a water and vaccuming.

I feel using a quarantine tank is good practice. If you come up with a sick fish you put him in there to treat. I also put new fish in there for simple purpose of I want to make sure that I don't intoduce any disease or parasites to my tank. It's a lot cheaper to treat a 10 gal than say a 75-90 gal tank. You also limit the risk of getting all your other fish sick.
 
I agree. A q-tank is better than a UV sterilizer, since many afflictions won't be prevented by the sterilizer--ich, for example, would still spread to other fish. Avoiding is better than treating, and a q-tank does just that.
 
If the cysts hatch, the tomites will be in the water column, and those that go through the UV filtration will be killed. Some of them will manage to find a host before going through the filter, and will hatch out another batch. The UV will reduce the odds and lower the rate of infection, but it will not stop the infection once started. If you use the UV as part of the q-tank setup, you're a step in the right direction, but not the cheapest route to take. Prevention is always more effective than treatment, and UV's do nothing to prevent fish from exposure and infection.
 
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