with the mod i found to ISRU deuterium - https://forum.kerbalspaceprogram.com/topic/228493-pri-a-small-patch-for-obtaining-liquid-deuterium-through-electrolysis-of-water/
it does that by using the fuel cell to turn water into deuterium, but now, i need to get water. but, the water mining functionality on the drills added by the mod seems to not work, or maybe only work in some spesific way I havent figured out yet, idk.
So, i still need a way to get water.
so far, the only thing ive figured out I could do, is ISRU lh2 and ox normally, and use the lh2 ox fuel cell ability to generate water, and then use that to isru deuterium fuel. it comes with some downsides, as it only works when I need electricity, so if I have large unretractable solar panel arrays, it will not work. so, im trying to see if theres a better way than that to ISRU water for the deuterium fuel.