my skimmer is giong crazy

[asherah]

I haven't changed or added anything to the tank. Last night it started giong crazy and overflowing. It fills with water over and over again. I dump it out and within 10 mins its full of water again.
I unplugged it because it was late but I have no idea why it would do that all of a sudden .
It's a aqua c remora skimmer. It's a fowlr at he moment with only 2 fish in a 30 gallon.
any ideas ? =/

I haven't even had my hand in the tank.. who knows..

asherah