F8Chapter of Waters
The ruling on water already used to remove ritual impurity
Does used water remain purifying so that it can remove ritual impurity again?
Hanafi
Pure in itself but not purifying for others; performing ablution with it again is not permitted.
Reference: Al-Hidāyah
Maliki
Pure and purifying; performing ablution with it is valid, though disliked if other water is available.
Reference: Al-Sharḥ al-Ṣaghīr
Hanbali
Pure but not purifying once it has separated from the limbs.
Reference: Sharḥ Muntahā al-Irādāt