Thanks again for your message, Jason. Already did that. I couldn't take another picture before he took it all apart in dusgust. The tank, not the sump overflowed. Take a closer look at the filter part (white cylinder). There are two pipes coming off of that, one that goes behind the main overflow that was plummed to the UV, and the other one coming out that was put on a valve that was closed. However, on the test run, before the bulb was put into the sterilizer, the water somehow overflowed the tank at Squiddly's great disgust and running for towels. I'm getting used to running for towels. Perhaps I will lose a lot of weight this way.