Water tank conversion

[Jentine]

I have two tanks under the aft berth. A 35 gallon diesel fuel tank and a 65 gallon water tank. Both are plastic. I would like to convert the 65 gallon tank to a fuel holding tank. I believe the material to be polypropolene, the same material that jerry jugs are made of. If I make the conversion, I would change the deck fitting and the fill hose.
Since the tank will only be used for storage, a transfer pump will be fitted in the same manner as the fuel tank pick-up (through the top with a near bottom feeding tube) and of course, a suitable vent.
Does anyone see any problem with the change?
Thanks

[DeepFrz]

Jim said:

Both are plastic. I would like to convert the 65 gallon tank to a fuel holding tank. I believe the material to be polypropolene, the same material that jerry jugs are made of.

Most often, fuel and water tanks are made with different material. IMHO you probably should make sure of the material before converting the tank to a diesel holding tank.

Deep.