This is just a small observation I've seen numerous times and I find it a little annoying. No big deal really, but I'm here for another bug so I will mention it
Sometimes I see water being pushed aside by a tiny amount of carbon dioxide. This really should never be possible I think. Like 1000KG of liquids to the left of the c02 tile, and there it sits 20g c02, refusing to be pushed upwards into the oxygen and replaced by the liquid directly adjacent to it.
Steps to Reproduce
Set up a pool of liquid with built walls, and a (2 tiles thick for testing convenience) floor extending along either side at the level of the liquid There should be an oxygen atmosphere in here for the dupes to breathe Deconstruct the tile 2 spaces to the right of the water, so that gas will fill it (carbon dioxide from the dupe doing the deconstruction, just a few grams), so that there's 1 solid tile between those few grams of carbon dioxide and the water Deconstruct the tile separating the gas and the water The water on the left doesn't immediately displace the tiny amount of carbon dioxide to its right (i assume because the carbon dioxide refuses to move upwards into the oxygen?) *edit: this report was kinda an afterthought, so I didn't test the steps, I'm just trying to reproduce one situation where I noticed it. Potentially there is the additional step to build an airflow tile above the one that will have the carbon dioxide in it, which renders the c02 unable to move upwards for the liquid; that would more accurately describe what I noticed most recently though I wanna say the airflow tile isn't always the culprit- i could be wrong there.
This issue has not been confirmed by a developer yet.