Argh...

[justahannah]

My filter is acting up, I'm sure it's just to spite me. I'm running an AC 110 (barely a month old) with a sponge over the intake. I turned it off so I could re-arrange my aquarium decor, waited for the dust to settle (I've got a sand/eco-complete substrate), and then turned it back on...it still had water in it from when I turned it off and it wouldn't finish self priming...I made sure it was level and it still wasn't going...so I manually primed it with more water from the tank and then it started making this weird, LOUD, grinding noise like the impeller is scraping on the plastic casing or something. So now I've got it dismantled, cleaning everything and I see nothing that would cause the noise. The rod looks straight and perfect, cleaned it out with a Q-tip, no sand or debris to be found, the impeller looks like it did out of the box...just slightly mucky water. I'm about to plug it back in, but thought I'd post to see if anyone had experienced something like this or could think of a cause in case it happens again...or keeps happening once I plug it in again.

[justahannah]

Plugged it back in...still won't self-prime (it sticks when the water's maybe 1/4" from the top)...the noise is quieter, and now happens in short (1-2 second) bursts with maybe 20-30 seconds in between where everything seems normal...although the longer I leave it plugged in, the less frequent it's getting. maybe I oughtta just leave it alone and pretend it'll fix itself... :|

[The Zigman]

Make sure the internal parts are firmly seated together..
The impellers on many filters are magnetic drive, and if they are not exactly in the correct position, they wont work right.

There should be a piece that holds the impeller in place, make sure that piece in installed correctly.

[Star_Rider]

Hannah,
you should see water moving if you remove the uptake tube.
if it is then check the seating on the uptake tube.
I have a bunch of ac's and the uptake tube needs a clean seat or it won't pull water. also try removing the prefilter to see if that helps.

I found on one of mine with a longer uptake it had problems priming.(prob needs a good scrubbing)
from the sound you are experiencing I would suspect fine sand may be a culprit here..I know my wallyworld version of the penguin has issues in my tank with a sand bottom.

how's the bacteria doing?