Hookah not performing well?

[codipassaro]

http://imgur.com/a/N4AoC

Album showing hookah and parts.

Hello, I have had this small-ish hookah for well over a year now. At first it worked wonders, but now it's performing very very badly. Just tonight, I had a session by myself, using al fakher shisha, with Exotica charcoals, the finger length ones scored into squares. The coals lasted a whole 10 minutes, and then I felt like I needed new coals. I'm using an xhale phunnel bowl, and i've tried to pack it tight and fluffy, each time I get almost no flavor or smoke. I'm using a screen, instead of foil at the moment as foil can get a expensive for as much as I use my hookah, and as much as I use foil for other things. I fill the base to the line, where it changes size, as you can see in the pictures, and I show how far down the stem goes into the water, about a inch. It bubbles and all, but I'm not sure if I'm adding to much water or not enough still.  Any help would be very much appreciated, and any further questions will definitely be answered! 

[Hookah Coals]

I will suggest you to use good Quality Natural coals .......