If you found that the water is running slower than before, it's time for you to clean the filter inside your tape. Normally, you can remove that filter assembly and have it shaked and cleaned. However, it will become less efficient over time, because more sand/small stones are stucked inside the filter. You need to diassembly the whole thing to remove the dirty stuff.
Don't worry, it's simple.
A small screw drive will help:-
After cleaning: