When I got home yesterday from work, I heard water splashing sound coming from the fish room. My heart immediately sunk. I got there, and there was no water on the floor, so I resumed breathing. There was a lot of water coming down the E pipe. After investigation and attempt to remove the gate valve, I was able to knock something loose. It was 1" Mexican Turbo. I have toothless overflow box, but I have a cover made of egg crate. It is not perfect, however. I should have installed strainers per some suggestions here.