noise reduction

Hi everyone, I really need help with a noise problem on my tank, because at this point I honestly do not know what else to try. My tank is an AQPet 50x50x50 reef tank (about 125 L display, with sump). The main issue is the overflow/drain noise. The gurgling is not mainly in the sump — the worst...

Can anyone help , how would you plumb this if it were your tank ? The display is a 60 gallon Visio tank with a corner overflow box , it has a 1” drain hole and a 3/4” return … I know , I know .. it is better to have an emergency drain but I got a good deal on it so I’ll have to deal with it ...