After building the Water Purifier, the dupes would not deliver Filtration Medium (for example sand) into it. I have other devices which need Filtration Medium too, like the Air Deoderizer. But in the second screenshot, the dupes would deliver sand into the Air Deoderizer. But they would not for the Water Purifier. After building it, I set its priority to 9. Then, I waited for two more cycles, but no one delivered any materials. I tried many methods to make it work, like reseting the priority, destructing it and rebuilding it, and saving and loading the save again. But none of them worked. I saw other people complaint about this problem too, but it hasn't been fixed. It is a good game with good designs, animations, and I hope that you guys can fix the problem, so that the game becomes more enjoyable (now because of the problem I cannot get any clean water, thus no bathroom, no shower, no clean oxygen from the electrolyzers). Thank you!
Build a Water Purifier.