Why are my fish stuck in one spot?

[kyle8544]

Why did my fish suddenly get stuck like this? I kinda wonder when this happened too cause all the eggs dropped in one spot.

 

[Knurek]

Pacus generally don't behave well in mixed liquids. If you use polluted water in your fish tank then you need to filter out the top layer of clean water that is produced by Gulp Fish. Otherwise your Pacus will get stuck. It happens when they try to swim from polluted water into a clean water tile with a low amount of liquid (they need at least 350kg/tile to swim). Pathing seems to stop working until the drop of water is removed from the tile they are trying to reach.
(I think it might happen because normally they would flop in these tiles with low amount of water, but they can't because there's not a solid tile below it, but polluted water instead.)

In your case the tiny fish hatched from eggs go to the feeder and after eating move to where all the fish get stuck because of the clean water around them.