It's possible that you have a blockage, on the toilet line and the water is coming up in the tub to alleviate pressure. Or, your vent may be clogged causing what is called back syphonage, causing the water not to push out.
You had better get a plumber in. The sink drain and toilet drain should not be connected as waste from the toilet could bubble into the sink which couyld be extremely hazardous.
It isn't. toilet water will sit in the tank just like tap water sits in the pipes, one is about as fresh as the other. Toilet water sits for a spell. If it sets for a long enough time, the chlorine will evaporate out of it. This takes 24 hours to be effective. Thus, it is cleaner than tap water, which has no evaporation rate.
it is run off of a different line from the main water supply. you may be able to trace it from the hot water tank and see where it branches off.
heavy objects than water can sink in water
The density of radium (5,5 g/cm3) is greater than the density of water (1 g/cm3); radium react with water with violence.
The Galileo thermometer is based on a thermoscope designed by Galileo Galilei. There are multiple bubbles filled with different colored liquids and tags that indicate temperature. They sink or rise when their density changes with the temperature of the water around them. The bubble that sinks the farthest is the most accurate temperature.
It all goes to the same treatment plant and is sent down stream to the next town or city. All tap water is the same, sink or toilet.
Call a plumber
Sink is not vented properly and the water from the p-trap under the sink COULD be sucked out by the hydrostatic pressure from the toilet flushing.
The washer in the shut off valve has probably split or come off completely over time.
It looks like a sink and toilet combined...It squirts water up ur a$$ to clean out any left overs
things that get flushed down the toilet sink bath all of that.
A water closet or a 1/2 Bath
There are a few reason why the water in a sink and toilet can be brown. It is possible that the pipes may be copper or galvanized, causing the water to change colors. Another reason may be that it is well water and it is not being filtered properly. Check with a local plumber for more options.
No air or any form of gas will always rise to the surface (as a bubble)
Rinse it out well with water from the sink or distilled water if you have it on hand. Then use eye drops to relubricate it.
The toilet itself is plugged or the pipe from the toilet to the drain is plugged. It may be that the tub and sink have their own drain pipe that may connect to the main away from the toilet drain. Plunge the toilet or sometimes if you fill a 5 gallon bucket with water and pour it into the toilet as fast as it will take it, that will flush out the line. It is a greater amount of water all at once an forces out what the clog is.
Anything connected to water pipes. Sink, faucet, toilet, shower and controls.