fuel tank placement - 23 center console

[thedink9]

Hi Guys
When I replaced my tank a few years back I intentionally move it forward a few inches. I cant remember how much however but it appears to be about 4", but I'm not quite sure . The trouble Im now having is the deck will not drain and water now sits forward when its at the dock!

I can get it to drain when I stand on the transom and I weigh 200 lbs.

Can anyone give me a suggestion about how far aft I should move the tank which by the way is 96 long and when full holds 131 gallons. Thanks Dink