Help with noisy sump and overflow

[Reefermike]

no not just the one issue . I have a marineland 90 RR tank. It has 2 issues, first the overflow duruso sounds like a rhythmic toilet flushing . Then is is compounded by the boiling as the water enters the sump. I use a mag 9 return and the pipe enters the sump and is submerged about 2-3 inches . This thing is driving me nuts to the point I want to downsize to an all in one . Any suggestions? It has always been loud but lately it seems much worse. Suggestions

 

[CodyRVA]

Have you debated a full syphon/gate valve: bean animal? Do you run filter socks? I've noticed when I use new socks, the water rolls off the plastic insert and makes all kinds of racket. My drain pipes are also submerged.

 

[Bdog4u2]

I partially cover the hole under the supply 90 on top of the overflow to quit the splashing noise but leave enough to break siphon if your sump isn't big enough to handle back flow during loss of pump. I also adjust valves to allow the pipes to fill mostly up