Help with bubbles coming down my drain line

[theMeat]

PVC pipe cutter. Fifteen bucks at Lowes

 

[theMeat]

 

[theMeat]

Thread 'Herbie overflow'
https://www.reef2reef.com/threads/herbie-overflow.766575/

 

[theMeat]

And you will hear you have to /should use a gate valve. A gate valve will allow for more precise adjustment. Have been using ball valves for 15 years on many tanks and they work just fine

 

[bambo]

Get your hands on a pvc cutter. Cut the pipe, glue in a valve, done.
Inside the overflow box you have pipes glued in?

Yes

 

[KStatefan]

Yes

The image you posted earlier also had a threaded section is that what you have?

 

[bambo]

The image you posted earlier also had a threaded section is that what you have?

The only threaded section on my drains are the actual bulkhead themselves