Help -Skimmer Overflowing Constantly

[DiverDude]

A couple of days ago I changed my filter sock. Doing so usually makes my skimmer go nuts (fill quickly with clean water) for a few minutes and this time was no different -except that it's pretty much kept going nuts for almost 2 days now.

I did a 15% water change and changed the filter sock again this morning in case something had got into the water but it's just as bad now if not worse.

I've shut it down because I'm tired of listening to it gurgle on a full (clean) collection cup.

Any thoughts on what could be causing this ?