I suck on my hand, which I use to make a cup on the end of the tube of the grabel vac. I don't suck until the water hits my mouth. I suck until the water reaches about 3/4 of the length of the hose, then the water pressure takes over and starts siphoning.
To me, it's much easier than shaking the vac up and down in the water and creating a tsunami in the tank.
To me, it's much easier than shaking the vac up and down in the water and creating a tsunami in the tank.