It looks like in the middle photo that the bottom of the overflow tube has a T. One side goes in the drain one side has the long section coming to the top of the live well and the other side is open. In the open side is where im talking about putting the plug which would allow draining. Nope. Just re-checked. It IS a T connection BUT front of T open horizontal, referring to it as the bottom fill tube and likely where the aerator hose would connect. Vertical part of T prolly the over flo tube and it does NOT pull out. The back side of the T is not open - its the drain/fill tube running to the transom. So...... Argh!!! Better photo maybe!
