2,010. Only by Day; Multiple Women

Hilchos Sotah 4:2

A suspected woman is only made to drink the bitter water during the daytime; this may be done at any point in the day. Two suspected women are not made to drink at the same time as the Torah says, “The kohein will have her stand…” (presumably paraphrased from Numbers 5:16).

Hilchos Sotah 4:3

If a suspected woman declines to drink out of fear, she has the option to change her mind and drink. However, if she says that she won’t drink when she’s in a healthy state, unhindered by fear, then she may not change her mind and drink.