I wanted to post this to see if anyone had similar occurances. I recently discovered a slow leak in my frag tank, but I couldn't tell where it was coming from since I couldn't get behind the tank. I removed about 80 gallons so I could move it and find the leak. The leak was coming from the overflow bulkheads which were very loose. I could tighten/loosen them by hand. This tank has been running for 4-5 years without any leaks. Has anyone had similar experiences with the bulkheads becoming loose over time?