Few Plumbing / stand questions.

[mark]

1. elbows and horizontal drain okay (one of mine is probably 20 feet)
2. okay to elbow before pump, just ensure pipe (and fittings) are not less than pump inlet
3. just below surface
4. you'll want a valve on you return so look into a union-valve for pump maintenance. Drains, I never bothered with unions as figured would just cut out a redo.
5. have BB never painted the pink foam under tank, though now covered with coralline never could really see foam as bottom glass acted as mirror