Here you go guys:
Sodium nitrate.......2
Amonium nitrate....1
Charcoal...............1
Both sodium nitrate and amonium nitrate are very cheap availeble fertilizers. All the components are powder, but sinds i have no ballmill, they aren't very fine.
I used a tube, with an inner diameter from 6 cm, (2.4 inch I think) and the tube itself is 2 mm thick. The tube is about 20 cm high.
I concluded the tube with a couple of centimeters (3 or 4) of sodium carbonate (gips). The hole I drilled was1 cm I think.
These fountains can reach four meters, and last a long time. Next time I'll take some pictures, and if possible make a film.