Reef octopus ext150 neck leaking

[Robertchrisroph]

hello and thank you. I have a reef octopus reef skimmer that neck is leaking. I've pulled the o ring and seems fine. About year and a quarter old. Thank you. I'm thinking that black ring the cup goes into?

 

[KorL]

Maybe needs a replacement O ring. Or a crack

 

[Robertchrisroph]

Found the problem. My screw holding on the air defuser was loose. Must be cracked inside the end of screw? Don't know really I know it's not leaking now. Thank you