Some mods such as Gregtech have many kinds of fluids, we can use a Fluid Reader to read a Fluid Interface, so we can read the fluid data from the entire network. But we don't have an easy way to read the quantity of a kind of fluid. It is different than we can easily read the number of something from the item list by using operator "item_list_count". So, I suggest adding new operator "fluid_list_count".

Thanks for the suggestion!

The Network Reader has an an aspect "Network Count Of Fluid" which will given an operator that returns the amount of any given fluid. Is this what you mean? Or is this in relation to some kind of fluid storage that can store multiple fluids inside of it?

I think @themorningglory233 refers to an equivalent of the item_list_count operator, which can determine item counts based on an arbitrary fluid list (independent of whether or not it's stored in the network).