Return is making bubbling sounds
 

One of my returns is making a bubbling sound that's driving me crazy. I have a 4 way, and it is the furthest one from the 4 way that makes this noise. The other 3 don't make this noise. Any ideas on how to make it stop.
Thanks

Do you have valves on each one to try and balance out the flow ?

put a piece of air line in it. That will give the air a way to escape and stop the gurgle

I don't have valves on them.

Where exactly would I put the air line tubing? I have anti syphon holes above the water line.

If it is making bubbling sounds it is probably getting air inside.

Solutions are to eliminate the source of the air or give the air a way to escape.

Hard to say what would work without seeing the actual system. An air line can sometimes be inserted to give air a way to escape.

Do you have large bubbles coming out of the return causing the noise? If so, a tee where the majority of water goes straight and the air goes up can eliminate the sound.
http://i274.photobucket.com/albums/j...F/return-1.jpg

Thanks very much. I'll give that a try.