Loud bubbles coming from my drains in dual overflow setup.

[Mmbra]

Today i did a test on all of my plumbing before bringing the tank into the house. While testing, my drains were blowing a crazy amount of air bubbles and it was super loud. I have dual overflows with 1"drain lines and 3/4" on the returns. Here is a vid i took. Any ideas what i can do to decrease this air volume? Thanks for the help.

 

[Kershaw]

Try raising your dorso. Or add a gate valve

 

[Mmbra]

Hey thanks for the quick response. So to be clear you are suggesting add a ball valve on both drain lines? Than i just adjust the valve until the bubbles stop?

 

[reefwiser]

The ball valves will raise the water level in your overflow. What is happening is air is being sucked into your overflow lines.

 

[Kershaw]

Gate valve not ball valve. Ball valves don't have to adjustment you need. Gate valves can make much small adjustments