If you know anyone with a sensitive nose, ask them if the place you live in smells musty or moldy. I’ve had family members go through similar issues also without any help from the medical system and mold was a major contributing factor. You and anyone else who lives with you will be nose blind to it and won’t be able smell it without spending a week or so elsewhere.

Liquid cooling is meant to be contained in tubes, fittings, and resevoirs. You have to use mineral oil if you want an aquarium pc.