7th floor of 12 floors.
10th floor and above has additional pump for water.
Water was shut off today so the tanks could be cleaned.
After turning the water back on, all faucets have very, very low water pressure. It isn’t air in the pipes.
Other people reporting their water pressure is fine.
Any way to fix this?
I’m afraid the only thing you can do is letting the water run for a while.
Or wait until the roof water tank reached full level? I’m thinking about the physics, but a bit hard due to TTL sake interfering 
Fixed it.
Lowest taps need to clear the air first.
It worked.
You can get a small stand alone pump installed to increase the pressure. Our flat has one. Only need to turn it on to shower but it does the job.
Things you can do:
Remove aerators from tap with a pliers or a wrench. Latter will not damage the Chrome so easily. And let the water run for some time, that should flush all the diet out. Meanwhile aerators can take a bath in warm vinegar.
The the shower fittings are mounted on Z-shaped pieces. In Taiwan they sometimes contain a valve try closing and opening them while the aerator is removed to loosen and remove dirt.
-Be careful with old fittings and valves as they can be sensitive.
-Don’t use excessive force.
Aerator:
That’s the problem with main building water towers. If it is shut off, water will come on and off for quite a long time. No idea why. At least last time I lived in such building it did that.
The house’s pipes gets empty and as most pipes here are more or less a rigid hose and not necessarily installed in a straight line you’ll get air pockets.
