Is this normal? Amount of air bubbles in return

[Meloco14]

Hi guys, this is my first tank with a sump and i did my own plumbing and DIY sump so I want to make sure everything is correct. The tank was used and had a basic single standpipe overflow, which I've read sucks down both air and water so bubbles are expected. I just want to make sure this amount seems normal. Thanks

 

[Reefer Reboot]

If you are using just one fully open pipe then this will happen. Can you put in another pipe to set it up as a Herbie style overflow?