If there is water spilled on the ground. The Duplicants will take the minimum amount of water possible then take it to its destination, instead of trying to fill up on the maximum liquid possible before trying to take it to the destination.
If you play the game on the fastest settings, you will notice it takes 1 full day to suck up the water with 4 duplicants and deliver it to the terrarium.
It is best explained by loading save and just running it on the fastest speed.
Yes I am aware I could have mopped it up. This is more of a logic issue - of units taking the minimum amount each time in one tile instead of properly filling up.
Steps to Reproduce
Spill water on the ground so a thin layer of water appears over a long stretch of ground. Create an object near by that requires water. Duplicants will spend days sucking and delivering water.
This issue has not been confirmed by a developer yet.