hey rebgirl that pink bong looks like acrylic, if you want a REAL bong go with glass. however, if you still want that one, the water goes in like the right side of the pic you added arrows to. the water level should be like a cm or so below the actual bowl (also take care if the water is high because if you inhale quickly and then stop inhaling, the water is gonna shoot up the stem onto your weed- happened way too many times with me before haha its always a bitch to have to dry the weed out after). the pink acrylic hole part of that bong is to break the big bubbles down into smaller bubbles. this helps filter the smoke better and offers a smoother hit.