If you’ve been smoking a few bowls in a row, like I just did, and each flavour tastes the same, pure junk, or worse as these photos might show
This is how you’ll feel
No un-salty water, you’re in the desert and are “pinning for the Fjords”.
It means that you are :Smoking too much, and/or need to drink since you have become as one thirsting in the desert. Drink something without caffiene.
Fruit jucise help for hookah smokers in this case. I’ve heard from people that even if you are NOT a drinker of alchoholic “bevrages” you may take a mixed vodka drink and swirls it in your mouth, to spit out. This cleans the palate and also makes it more sensative to taste. Drinking lots of vodka will dull the brain which will dull the sense of smell and taste besides turning you into a .
Monty Python “Parrot Sketch” humourous classic :
http://youtube.com/watch?v=GipFyAsYK1M
¬†Same “Parrot sketch” but in Nigeria !
http://youtube.com/watch?v=LvyrzQldOKE
Also, try changing to  a fresh hookah hose
Or try mint flavoured shisha
All the above available at Smoking-Hookah.com
Mint tea
or brush your teeth, mate!I don’t use any particular brand, but mix with a bit of mint toothpaste and water.Each to personal taste.
The baking soda helps clean teeth and makes healthy gums, kills germs and is great (without the mint) to use a solution of very little baking soda to clean your metal shaft, but rinse well so it won’t rust, but for cleaning the glass bowl you may use a higher % with warm water to clean off impurities with the brush or baby bottle brush!
So, a few good ideas have been mentioned. Maybe you need to clean your hookah.
Most probably, its a total combination of ALL the factors.
  Hookah 1