Fill clean water tank weighing from 9 kg to weighing instruments at all. If there is no clean water bottles may be used as a 1-liter bottle (1 liter = measure is kilogram approximately equal no actually haha but shifts.
Fill clean water tank weighing 9 pounds in the scale of it. If not, it may take a bottle of water and a liter bottle cup (1 liter = 1 kg, based in fact, not only me, but the shift.
Add water 9 kg in a tank weighing from the scale. If there is no water bottle may use a liter bottles measured (1 L = 1 kg approx. Actually, แล้วไม่เท่ากัน. But shifts can be.