I woke up this morning to my 2213 making a rattling noise I thought it was an air lock so I was shaking the filter to no avail. So I took the filter apart and the ceramic shaft was snapped in half. My question is would an air lock cause the shaft to break if ran too long under those conditions? I have a fluval surface skimmer on the intake and thought maybe it got stuck and started letting air into the filter. I ordered 3 new shafts off of fleabay for $27 shipped. But now I am without co2 and a filter until I get them and only have a powerhead with a filter on it for filtration in my 29g. All in all I just want to know what could of caused this. The filter has only been running for 2 months since I bought it. Didn't think it would break so soon. Any help would be greatly appreciated. Thank You!