Dear Yuen Foong,
Haha ... I think your wife has perhaps a little - overreacted. Everything is gonna be fine.
Water, in the practice of Feng Shui refers to actual bodies of water - like a river or lake. And in the house, a swimming pool, pond or aquarium. Nothing about 'mop buckets' or 'water basins'. So DO NOT WORRY.
Now, please explain to your wife that the FUNCTION of Water in Feng Shui is to help collect, barricade or activate Qi in an area. And to do this, it has to be in substantial quantity located in a specific direction/location for extended periods of time. Water, by itself, DOES NOT generate any positive or negative Qi. So even if there has been dirty water poured on the wash basin - SO WHAT? It does nothing to the Qi of the house. (Meaning it won't affect the Feng Shui).
Keep your wash basin. You don't have to change a new one.
Remember - practice Feng Shui with a LOGICAL mind. For every feng shui application, there must be SOUND logical explanation, based on sound feng shui principles.
Dirty water on basin = bad feng shui is pure nonsense.
Warm Regards,
JY
