You need to experiment. You also need to know what wetsuit your using. Full, one piece, farmer john, shoprty, 3 mil, 5 mil, 7 mil. You need to have your wetsuit and a weight belt AND BC. PLEASE tell me your wearing a BC!! And go play in the water. Experiment with the weights till you find netural bouyancy and then add a little more. You want to be on the bottom and not be bounced around BUT you also need to be able to swim up.
AGAIN. ALL this is taught in a DIVE SHOP. If your using a hookah without being certified YOUR risking your life. Do you know how to handle the water if your mask strap breaks? Do you know how to clear your mask of water if it comes off and you need to put it back on? Do you know how to ditch your equipment?
Your asking a dangerous question here and there is absolutly NO answer that fits everybody.