Filling a bong that does not come accessorized with a percolator is very easy. With one, there are some steps that need to be taken into consideration.
It is very important to ensure that there is enough amount of water in your percolator bong. The purpose is to ensure that it will properly cool while functioning well. Filling a percolator bong is quite easy. Most models are referred to as tree percolators, which means that they need to be filled right from the top.
All you need to do is to fill it right from the top, pouring in some water until you notice that the water is enough in the lower chamber. Water flows through naturally in this direction. When this is handled well, the percolator will be half-filed.
The secret to this is not doing it too fast. When you notice that the water continues to flow through and cannot get the percolator filled with water, you may want to try doing it slower the next time. This is to make sure that the water is not sucked or pushed down by the change of pressure levels in the various chambers of the bong.