Our water supply is fluoridated (Victoria, Australia). Bath has not been in use for a long time as we prefer showers. Gas hot water recently changed over, but don’t think that would have made any difference, and ran the bath with cold water after and that was also blue tinged. Our water tastes just fine though. Believe we have a mix of copper and pvc pipes.
Many of our white porcelain fixtures were stained blue from copper leaching from the pipes due to acidic water. A pH treatment system was installed and the problem disappeared.
I friend had an old bathtub. The stopper was metal, but rather corroded. No one made those anymore.
So, they took it to a shop that plates metal.
They paid to have it cleaned and electroplated.
It is illegal to do that here in the states if you want chrome for some reason so they had to nickel plate it.
They installed their shiny new looking stopper and filled the tub.
Water had a clear blue tint because of the nickel reflecting blue light in the water.
If your water is actually some kind of color (put some in a clear glass and look), you have a problem.
You may have to call a plumber to investigate and repair what is wrong.
Copper makes things blue. Do not drink the bath water.
I’ll go with the light refraction theory and also suggest you dip a glass into the water and then hold it up in a different light to see if it really retains a blue-ish tint-
could just be an optical illusion based on colors in your bathroom.
That is merely a optical illusion NOT caused by copper pipes etc.
Dip a clear glass into the tub then hold it up to sunlight and you will see it’s perfectly clear.
The water is merely filtering certain frequencies of light and is more noticeable the larger the deeper the water.
You can see the shallow end looks nearly clear.
I can tell but the harsh lighting you are using no less than 5000K LED bulbs.
And using high temperature LED bulbs makes it worse since they produce alot more blue light spectrum.
It’s from the copper.
Tends to be worse if your water is acidic in nature.