Why my bath room tape no water or very small every time after the reserve tank at the roof goes empty?

But the water tape in the next bath room on the same floor has no such problem.Why my bath room tape no water or very small every time after the reserve tank at the roof goes empty?
The tap that has no problem MAY be fed from the mains. Try turning off the mains stopcock and see if that affects your ';ok'; tap.Why my bath room tape no water or very small every time after the reserve tank at the roof goes empty?
Check for sediment in the end of the tap. It should unscrew fairly easily.
Because your water tank has a blockage in the ball valve which makes the water tank fill very slow. The other tank may be fed from another tank. You are taking water from the tank faster than it can refill.
There's a website that I frequent for questions just like this. It's kinda like This Old House - check it out!
maybe a slug has got in the plumbing and is causing a blockage you will tell soon as the water comes rife when you shower