Water tank

[Skipper599]

I need to install some plumbing for my potable water tanks.

I have three aluminum tanks, all located under floor, above the encapsulated lead ballast.
I want to install: - 1) a fill pipe, - 2) a supply to two sink units, - 3) plus vent hoses. The latter pose no problem as far as I can see, and I think I can deal well enough with supply hoses too. They will be flexible, and all I need to do is route them through the cabinetry.

My main concern is with the Fill. -
I'm thinking of a rigid plastic pipe of some kind, fastened to the underside of the floor beams, with a spigot feed leading to each tank - In effect, a manifold. -

Then of course, i need to lead the Fill to an "on deck" fitting or wherever appears easiest to install. - This may well pose a challenge.

I've been told by a friend I should NOT use "ABS" pipe for drinking water. So what should I use?
Of course, he also said I should not have used aluminum for the tanks - but it's too late now, they're built and installed.

Any and all thoughts/comments greatfully appreciated.