As an alternative to liquid through buckets

Well, almost done.
One question: how we should display fluid requirement? Two ways: as fluids (sic!) and as fluid containers. I prefer first.

I prefer first too. This is consistent with refinery.

Note that we need to display liquid containers as well, a bit like in the engine interface.

Yep, I know. I've plane four liquid containers with erase buttons, like this:

wouldn't it be better to make those "select buttons"? so you can select a tank and that is the tank that is filled up, or drained if you are draining fluid back out of it (unless you don't want that)

Drain shouldn't be allowed for builder I think.

Let's start with something simple, there's already a lot of addition here :-) @Prototik, I think your proposal is reaches enough in terms of functionality.

Not every mod supports Buckets. I think builder should request a FluidContainer instead. With the same amount as the block require.

Why not both?

@Speiger @dukejuke both are definitely in order :-)