How to get a good seal, and I dont mean sea creatures, you want to set your hookah up the right way. First are you putting it together properly? Make sure to wet your grommets before putting your hookah together, this will make sure that they go into place and seat well. Is your ball bearing in the carb working properly? You should always take your carb apart and clean it after each session to make sure no build up or corrosion happens to prevent it from making a tight seal. Are your grommets in good condition? Make sure there are no cracks or tears in your grommets to avoid leaks. Is your hose in good condition? Always have a backup hose just in case it breaks or cracks so that you arent losing a good seal and losing smoke. If you have put your hookah together properly there are 3 steps to follow, hand suck and listen. First place your hand over the bowl and suck through the hose, now listen up and down the hookah to hear any leaks causing you airflow where you dont want it. If you hear a leak then try to take apart that piece and put it back together to see if you can fix the leak. If its from a grommet then use some water to lubricate it before you put those parts together to give you a better seal and to seat the parts together. Remember to always put your foil or screen on as tightly against the bowl as you can so that this part is sealed well too. Just follow the 3 easy steps to find any leaks, hand suck listen, and you will never get a bad seal.