In faith they always pray before lauch krathong into river.To express their appreciation to the benefactor of the river to our water xinsumption,water use,as well as ask for the Holy ganges river and their condolence for the wastes were dumoed into the water,which causes the water is not clen someone may be put down the nails and hair into krathong.they believe that a bad thing is eliminated from you.the coins are put into.to bring prosperity to you.