UV Effects on Skimmer Output

[midgetwaiter]

I came home today to find my apartment smelling like low tide, really nasty. I figured a tank had busted but they were fine. Nothing dead, I couldn't find the source of this smell. After having given up I was filing my ATO up when I noticed that my skimmer cup was pretty full after only a few days so I pulled it out to empty it and figured out where the smell was coming from. I got it to the bathroom and poured it into the toilet and very nearly tossed my cookies. It was the foulest stuff you can imagine, 2 hours later and the bathroom still reeks.

I'm happy to see my skimmer performing but a little concerned as well, I'm surprised to see a change like that. The only thing I've changed recently is adding a UV sterilizer and I'm wondering if that could account for the change?