Foam in sump intake

[pizzaguyohio]

Need help. New too saltwater and my sump I take is foaming. I don't know why.
1in intake derso
3/4 return Aquion 3000 pump

 

[JC1977]

This happened on my single drain system . My best guess was the single drain allows air to mix with the water as it enters the sump and I was trying to push too much water through the single drain. In essence it acts almost like a protein skimmer. I reduced the amount of flow and shortened my drain pipe and it helped but didn’t go away completely. That’s my best guess anyhow??