Overflow Gurgles!

[shaywood]

I set up a new 125g tank with an internal overflow, which won't stop gurgling! Every 3-5 seconds it puts out a loud gurgling sound, like it sucking air. I'm using a Mag 7 as my return pump and have a separate closed loop system using a Dart pump, which isn't turned on yet. Inside the overflow I have a perforated PVC pipe.

Any idea what I can do to eliminate the noise? I have tried removing and inserting filter spounges in the overflow and making adjustments to the spa tubing underneath the tank.

[Steven Pro]

Search online for instructions to build something called a Durso overflow. It is a PVC assembly that should quiet down your tank.

[chrisbrph]

Quick fix- To resolve gurgling in the past I have placed 1 BioBall that was small enough to fit inside the perf PVC but large enough not to fall into the sump through the drain fitting. The problem is that the water that is flowing down into the sump has created a vaccuum- the force of the water flowing through the bioball will reduce the vaccuum (breaks up forceful stream) - stoping most of the "gurgling"

If you do try this method- keep sponges in to trap waste and make sure the water drains fast enough through the overflow to keep up with the return pump.