Hi, small question, by accident I put capacity to 2.500.000 instead of 250.000 and noticed that if will fill up to 449k, I presume it stopped at 449 999.
Is there a limit.
Thx

Bump. I have same question ... I cannot get more than 499k into the tank.

So its the depth of the fluidbox, and how it interacts with the factorio fluid mechanics. My feeling/understanding is that you can't overcome the shallowness of the tank with the pressure, so if you put the tank "deeper" it increases how much can go in the tank before pressure stops it. In practical terms, if you change the base_level of the fluid_box of the storage tank entity to a lower number (-100 or whatever), it takes more fluid. I don't really know the exact details of the pressure changes as I'm not a factorio modder and haven't done extensive testing.

hmm it could certainly be some problem in regards to the internal fill level of the connected fluidboxes

I now have the full 1M fluid. Thank you!
I edited prototypes/tank.lua as dtp11 suggested, then saved the modified zip file.
fluid_box = {
base_area = base_area,
base_level = -100,

This has been properly fixed with version 2.0.0, thanks again for reporting :)

note: the settings got renamed internally so make sure to recheck them after updating to get the values you want!