Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions.
As to what follows:
In response to your question, we say, and with Allah Almighty lies all success:
Many people avoid using water that has been recited upon (with Qur’anic recitation), or with sidr water (lotus leaves or its powder mixed in water), or with Zamzam water in bathrooms. I do not know of a source for that, neither from the Qur’an nor from the Sunnah, other than that it is a form of honoring the water that has been recited upon, and Zamzam water. I hope there is good in such honoring, but I cannot say that it is not allowed, or that it is disliked to use these types of water or these questionable things in the bathroom, because there is no evidence for forbidding it, and the basis for Islamic rulings is that of permissibility. Furthermore, if there was any harm or impermissibility, the Prophet (peace be upon him) would have clarified it. Allah Almighty said:
“He has explained in detail to you what He has forbidden you, excepting that to which you are compelled.” [Al-An’am 6:119]
So Allah has explained, and made clear and simple, whatever is forbidden and prohibited in His Book. Likewise, the Prophet (peace be upon him) clarified that in the Sunnah (through his life and teachings). So we limit ourselves to what has been mentioned in these two (the Qur’an and the Sunnah). But whoever wishes to avoid something due to caution, then it is up to them.
And Allah knows best.