Plumbing/overflow question

So, this is my situation. I've got the 120 all plumbed and running. everything is working great. But, the noise from the overflow is crazy.
I've got dual 1" overflows, teed into a 1 1/2" into the sump. It sounds like it's just trapped air cause it's a bubbling sound, that's not constant, but gurgling. I'm wondering if there is a fix? My current idea is to install a bushing to create slight downsize and therefore back pressure reducing the gurgle. Am I crazy? Lol
Let me know what y'all think....thanks

 

Are you running a Durso or Stockman style standpipe? If not, that's the place to begin. If you are, then it needs to be properly vented.

 

Durso style. 120 megaflow. I'm about to do a search, but what's the proper way to vent them?

 

Most folks vent them by drilling a hole(s) in the cap on the T fitting on the top of the standpipe. Sometimes they require multiple holes, sometimes no holes.

The best way to begin is to take a 3/16" drill and add one hole and see what happens. You can shove a short piece (1") of rigid airline tubing into it and attach a short length of airline tubing and an air control valve. This will allow you to tune the single hole.

I have some Dursos that are not vented, some have one hole, and some that have 3 or 4 holes in them. You can also tune your tank for max quiet by adding a T and a ball valve back to the sump, which allows you to adjust the amount of return so it's "just right" (generally, this is for a pump that's just a bit "hot", but still matches with the drain's flow rate).

We usually start our Dursos out with a larger ID standpipe than the bulkhead (e.g., 1.24" stand pipe reduced to a 1" B/H fitting).