While realistic, it is not practical for example the ore processing. When pumping fluid out from a vat, it seems impossible to pump out a solution with the same concentrations into a basin which becomes an issue as basins can only hold two "unique: fluids.

It's not particularly realistic! 'Realistic' would be that they mix together when added to the same Basin. Which they now do. Fixed in 0.4.

This has been reverted in 0.6. You can just use a Mechanical Mixer to combine the different fluids.