[kyle3]

After my last tank maintenance session where I cleaned the pre-filter (not the main filter media chamber) I was emptying the bucket of tank water I had used to clean the sponges and their plastic housing. Near the bottom of the bucket I found a little gray plastic part and I COULD NOT FOR THE LIFE OF ME figure out where it goes! 🤦🏻‍♀️

Can anyone tell me what this little piece should go?

The internet has failed me so far - which is probably because I’m not sure what search terms to use.
here is a link to my model of filter: OASE BioMaster Thermo 250

photos of the offending part below:

 

[stlhokie]

Looks like it's something from inside primer, as seen here in the manual:

 

[kyle3]

@stlhokie THANK YOU!

I must have flown through my manual too quickly, because I completely missed this 🙈

thank you, thank you, thank you!
I was worried about what might go wrong - I feel so much better 😃

 

[evil8]

I just put this same filter in service yesterday. Glad you got it figured out.