1.6 GPF.
about 8 liters
If it's a normal household toilet you simply lower the water level in the tank that's over and behind the toilet by adjusting the fill valve. There are many different designs so I can't tell you how on your particular toilet. Some ae as easy as turning a plastic screw and some are a real pita. If you adjust it and raise the water level too much water may run over into the overflow tube and it will just keep running. If you lower it too much your toilet may not flush completely. Generally I adust mine as high as they will go without overflowing in order to get a stronger flush. I have never needed or wanted to turn down a flush.
Usually the water filling up the flush valve in the tank. If it's bugging you, you can change the flush valve to a new one.
* In the US approximately 40% of all domestic water consumed is flushed down the toilet. * an old-style single flush toilet can use up to 5.5 gallons (20 liters) of water in one flush, whereas more water efficient dual flush toilets average less than 1 gallon (4 liters) * replacing a traditional single flush toilet with a water efficient dual flush toilet saves about 21 gallons (80 liters) per person per day.
They are usually about 24-26 inches high
Your water lines aren't properly isolated. when you flush the toilet and your water lines are refilling with water it can create water hammer. This is usually worse if your water pipes are either not properly supported or come in contact with wood joists or studs. You may also have very high water pressure which means a lot of air comes through with the water, try closing the water inlet a little. A loose washer on the shut off valve for the toilet can cause the jackhammer sound you describe.
Due to the high number of different types of toilets in Hong Kong Island , Kowloon , the New Territories and outlying islands Hong Kong, flush volume varies.
You can try to fish what ever is blocking the passage with a bendable tool or you can shut off the water valve and take the toilet outside and flush it with a high pressure hose something like a pressure washer.
not all toilet bowls and tanks are compatible. If your toilet bowl has no holes for a tank it most likely a bowl that is made for a flush valve, or a high or low boy mounted tank.
Ferguson's ProFlo PF8200 Series High Performance toilet 3" flapperless flush valve empties the tank in less than 3 seconds 8"x9" water surface bowl height without seat: 17 1/8"
it smoked to much.. Its clogged
water energy money