Yes, the cans would have to be elevated. We put a towel on the sundeck and then set the can up there. It works great. I started with the shaker siphon mentioned above and it works great. It's a game changer - I will never pour fuel cans again. But then... I learned about this: https://www.turbosiphon.com/ and it is amazingly fast. I only wish they had a small diameter nozzle on the end so that it could fit in normal automotive fillers - I need to do my own mod.