I had a few leaks in my walls, just on the rear support walls, I was really questioning whether or not this needs to me watertight. I thought about just drilling some holes in the acrylic and then the water would be able to cycle through, yet I concluded that wouldn't really do anything unless I wanted to put a powerhead or something over there....and I don't. So watertight it is.
Picked up another tube of silicone and away we go.
and by the way, you should get that bbq site back up, I had a online kitchen video, cookingwithbrett.com, but my server crashed and I lost everything, which is a bummer.
Eheim Pimp # 240