[Avalon]

I don't think a UV filter is necessary all the time. I would say when you add new fish, plants, or when any type of free-swimming pathogen may possibly enter the aquarium. Of course, bacteria, fungus, and algae can and typically do enter the aquarium at any time.

To be honest, my UV filter was a waste of money. It hasn't done anything for me. Sure, it can help cure ich and green water, but I haven't had either in many years, well before I bought the thing. UV's are like insurance: You know you don't need it 99.8%, but you know the time will come when that 0.2% will come. Usually when you least expect it and are feeling good about things.

And I buy ALL of my plants from dedicated hobbyists. LFS store suck for good plants, although there are a very select few LFS's that offer good plants. None are in my area. I'll have some plants for sale soon. No one really sells plants to make money. The best you can hope for is to help recoup operational costs such as ferts, CO2, etc., but most of all, you're helping a fellow hobbyist out.