Any oday 25 owners replaced the water tank? The po removed it and all the hoses. I am going to replace mine and I am thinking of building one out of some 12 inch pvc pipe and mount it to some kind of frame work in that cavernous area under the cockpit. I can get a stainless deck fill from west marine, but what do you do to install a vent? I am thinking 12" dia x 36" to give about 15 us gallons. I think it would be very cheap to build. Anyone done this?