Reading this whole argument it baffles me that all these atheists try to disprove your logic by inventing things like a water cycle.
There is however a much simpler explanation to the amount of water currently on our earth. It explains why we have so much water left over, yet still the world could be three billion years old by your calculations.
Simply put: the earth started off with more water!
Yes, there may be 1.4*10^21 liters on earth now, but when the earth first came into existence it had approximitely 10 times more than that. This means, that in those 3 billion years we used up 90% of all water and the remaining 10% is what fills our oceans currently.
Of course there isn't enough room on earth for all that water, but God himself had a solution for this, which is proven in scripture. Part of the supply of water was stored in heaven:
"And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so. And God called the firmament Heaven. And the evening and the morning were the second day."