I say, and with Allah's success: It is that which does not come to mind when the name water is mentioned. The observer cannot call it water without a qualification, such as saying: watermelon water, or something similar. Thus, the name water does not apply to it, unlike absolute water. The ruling on qualified water is that it is pure but does not purify from ritual impurity. It is permissible to remove actual impurity from clothing and the body with it, but it is not permissible to perform ablution or take a bath with it. The qualified water is only considered similar to absolute water in terms of its ability to remove actual impurity, but not in terms of lifting ritual impurity; this is due to the condition for such similarity, which is the complete removal of the impurity with the washings, and this condition is absent in legal impurity due to the lack of tangible impurity on the limbs of the one in a state of ritual impurity. Ritual impurity is a legal matter that has the ruling of impurity, preventing prayer while in that state. The legislator has specified a particular means for its removal, so it is not possible to equate anything else with it. Refer to: Maraqi al-Falah, p. 26, and Bada'i al-Sana'i, 1/15, and Halabi Saghir, p. 37, and Allah knows best.