- Open your factorio mod folder (Google it if you don't know where it is)
- Locate SmallFluids_0.0.1.zip and open or unzip it
- Open data-final-fixes.lua and change the fluid_value_divider to 0.1, or whichever value you prefer. 1 is vanilla, anything below that makes fluid costs higher
- Save or re-zip the folder and make sure it has the same name. Updating the mod will erase this change