We nor anyone else will be able to tell what is the problem as long as you do not art to isolate it. Just blaming us for the current situation will not solve the problem.

If I go back to your first post you said that AFTER changing the system the aquaero does not work correctly so I assume it was working before? If this is true it should be pretty obvious that something that you have changed lately is the root of the problem.

As said a few times before: test it outside the PC with a different PSU. Connect only one aquabus device to test them one by one. For the flow and fill level sensor you have to use a 4-pin aquabus connection because otherwise they will get not power when not connected to the PSU. The pump could be only tested when it is powered the normal way; aquabus can not power it. If it is connected via aquabus but not powered, it will cause the aquabus communication to crash. Also keep in mind that the aquabus is not like plug and play so every time you change a connection shut down the power at first and start over again.

Just in case it works now you could test it inside the PC by disconnecting the PSU from everything else but the devices that you want to test. As already mentioned: try to power the pump and the aquaero through the same line. The PSU can be started by shorting the green and any of the black wires inside the large ATX24 plug. A paper clip would be enough. As long as it shorts these wires the PSU will run. It might be possible that it will not start up when also the pump is connected: in this case the PSU interprets the high current draw of the pump when spinning up as short-circuit. Adding some more load like hard drives or fans etc. can help to avoid this problem.

Well, the problem will not be solved if you only sit there and hope for a wonder because this will not happen