noisy overflow

anyone have any idea why the return tube in the overflow on my aquarium is making a gurgling sound and spraying into the overflow the spraying is coming from a small hole at the top of the return tube it is factory done i believe its a siphon break? its like a mix of air and watershooting out, but if i put my arm into the tank to work in it, it stops. the plumbing is all pvc, tank is roughly 1 year old, marineland brand ,wasnt sure on getting marineland but 60% off was to good to let go ,have checked all connections but nothing there anyone have any ideas ?

 

The small hole is a siphon break for when you lose power to keep the water from going back into your sump and causing a flood. See if you can rotate the return so the hole is at the water line or spraying into the water.
The gurgling is probably coming from the overflow line going to your sump or from the water falling into the over flow. I would add an extension to the overflow line to the sump to raise the water level in the overflow. Putting a u elbow on the overflow line so that the water flows up the tube before heading to the sump helps quiet it down. I believe it is called a Hofer gurgle buster.