What was the kiyor in the First Temple? How did they deal with these overnight issues and source of water etc. there and in the mishkan? 3rd Temple Yechezkal says?
Howard G Schild, Monroe, CT
The Kiyor in the First Temple was actually ten Kiyoros according to the description in Melachim I 7:38. Based on this we can presume that there was less of an immediate problem of Linah, as they could empty the water from one Kiyor and fill another. The same logic would apply in the Mishkan where they had a smaller Kiyor which only had enough water for four Kohanim -- Moshe, Aharon, and Aharon's two remaining sons.
However, because Ben Katin built a huge Kiyor with 12 taps it became less practical to empty the water from the entire Kiyor and therefore he devised the Muchni to lower the water into the ground and prevent it being disqualified.
As for the source of the water, there was an overground channel bringing water into the Yam and the Kiyor (Yerushalmi Yoma 3:8), but in the Second Temple there was an underground Amah, a subterranean channel which brought the water to Har ha'Bayis and the Kiyor.
Regarding the Third Temple, Yechezkel doesn't refer to the Kiyor, but the researchers from the Temple Institute in Jerusalem today have built a huge Kiyor in anticipation of the Temple and have fitted it with a contraption enabling it to be lowered into the ground.
Yoel Domb