Re: Please help. Need the help of real Shisha/Hookah experts. (long)
personally it sounds like a heat issue.... not so much with your pack or anything else really.
The foil does let the bottom of coals go black.....especially if you just light the coal and set it on the foil. The foil draws the heat of coal like a heatsink causing that part of the coal to be cooler than the red hot stuff at the top.
I'd try using slightly more coal.... then work your way up to what you need.
Im understanding that you were using quicklights before the Jap coals?