Didn't really discuss the details with the contractor. No bottom-drains, that's sure. Bottom inlet into filter area, return pipes are all in the drawings, not sure how he'll integrate them into the pond-walls They did pour concrete walls and floor yesterday, so we'll find out soon enough..Have not read all the posts sorry.
Will you be using bottom drains and putting TPR pipes into the walls before pouring concrete? To create water jets so you can direct water to push bottom mulm (self cleaning)?
Below status as of this morning. Outer shell poured.
My guess is that he has poured the inside shell first, then fit all pipes on the outside and then cover that. Can imagine he'd fit all pipes close to the floor and pour a concrete platform over / around it. Inside of the pond will be epoxy paint to waterproof it.
Sure nothing will be allowed inside the pond, as the sweet occupants will move and/or destroy it somehow or other.
I had those 25-30kg concrete covers over the bottom-drains in the old pond. They where moved around constantly! Guess the RTC's are the culprits there.