Filter Issues

[goose22]

i did a water change today, after loosing a siamise fighter and 2 molies, it was due but id been ill. so disconected my Fluval 206 from my FISH POD 120, cleaned everything, pt it back together, now the bloody thing is surging, Makes a loud wooshing noise then stops for a few mins and does it again.
i had put a spay bar on but had to remove it as it was whistling when the filter surged.
any ideas folks, its doing my head in!!!!!!!!!!!!

 

[TwoTankAmin]

That sounds like air buildup inside the filter. I do not use Fluvals, so I am not sure how to clear air out if that is the issue. My Eheims always work out any excess fast if I fail to get them totally filled before turning them back on.
 
Also, make sure something is not blocking the impeller causing it to stick and free up and stick etc.