A few months ago I thought I read a Squidd post to keep the seal to the outside and the nut to the water. It was difficult to reach 36 inches into the overflow to tighten the nut but I hard plumbed it up completely only to find a leak. What a pain to reverse! Squidd straightened me out after that. A lot of waisted time and money on the plumbing. My local pet store also said to keep the gasket to the water to prevent dry rot years down the road.
Squidd, It only took me 6 months and alot of $$ but I've got my 150 going now! Pictures in a few weeks.