Soccer ball releases air fast?

I have a soccer ball. It is a Manchester United size 5 ball. I bought it last year. I did not use it for a year, so I deflated it last year. Yesterday I inflated it. It inflated properly and all. But, after 4 hours, the air had gone down. I tried pushing the ball into a bucket of water to check for punctures. There were air bubbles coming out of all the seams. How do I fix this?