Fluval Fx 5 Filter Blowing Bubbles?

[Fluval-1200]

Just bought a second hand fluval fx5 filter, and it keeps blowing little bubbles. Ive blocked the little tube in the lid which is ment to be a problem but ive still got bubbles. If I take the lid off and put it back on my bubbles disappear for a couple hours.
Anyone know how I can fix this for good?

 

[KirkyArcher]

I take it there are no poor connections on the hoses and that the intake is not sited near any aeration, some times it just takes time to expel all the trapped air.   

 

[Fluval-1200]

hoses are supertight, not near any air stones
when the filter turns off every 24hours a lot of air comes out when it restarts

 

[KirkyArcher]

http/www.youtube.com/watch?v=I3EuQ3UVPBQ  may be some answers on this youtube link 

 

[Fluval-1200]

hmmm I have a polishing pad in the top tray, il try with that out. Il report back in a couple days

 

[KirkyArcher]

You do realise  that the Fx5 runs "upside down" the bottom trays are where polishing pads chemical filtration should be installed with the coarser filter media is up at the top and biological stuff should be placed in the middle!

 

[Fluval-1200]

No I didn't know that lol, im planning on just using the fx5 as a bio filter and running a 405 as a mechanical (full of floss)

 

[Fluval-1200]

took the fine foam out and still had problems, then I noticed how my air was not coming out the filter when it does it 24hour purge.
People who run this filter make sure your outlet goes straight up and not sagging down, this is why my air was getting trapped and not purging.

 

[scotty]

maybe it is a west ham supporter