Hi guys, I bought a Fluval Venezia 190L tank and, as I haven't had a tank with an external filter before, I asked a friend to help set it up. Unfortunately, he has put the intake and outtake pipes in the wrong holes. So, now I have the intake pushing out water. He doesn't know how to change the pipes with the tank full of fish and water. So, I'm stuck. Can anyone help me, please?