With my aquarium pump, I'm able to inflate for about 17 minutes before I feel like I'm seconds away from bursting. Water Inflation, on the other hand, is a different story. I got a new water pump a few months ago, and holy pop! My belly gets a full 35 inches bigger from its initial 35! I feel so heavy by the end, and I feel closer to popping than ever, but when I sit or lay down, it feels... good(?) Definitely odd, but in a pleasant way.
Fun Fact: This was my most recent attempt, just moments ago.