I have a 70 gallon tank that needs a UV. I'm getting a UV not because I've ever had ich or any other disease - in 8+ years. I'm getting a UV, because my water is always a tint of dirty green. I really don't notice it that much, until I do a water change, and look at the water in the empty white salt bucket.
So, with a 70 gallon, do I need a 25 watt? or will a 15 watt suffice?
Like everyone around here with skimmers...everyone buys a skimmer rated for a larger tank.. So do I get the 25w...and then theoretically I can run the bulb for more hours, and it's still effective, even if it goes down to 50% effectiveness based on life of the bulb?
Then, what flow do I put through. All the UV's have ratings for max flow...but what is the minimum flow? or the perfect GPH flow I should use if I want to kill any possible "bad thing".