My RD somehow got hold of my small filter in the tank and dug it into the sand, I turned it off and cleaned it out abit but its stopped working. I was thinking maybe its just some sand inside the filter and that its not really broken seeing as its just sand, o you think I should pull it apart or once sand has got to it its gone?

What kind of filter is it?
It can't hurt to try taking it apart and fixing it, if it's not working at the moment you can't break it more than it already is.

Take it apart and give it a good clean out.

Try giving the impeller a kick start too...they can occasionally seize up.

I agree with Steve and take it apart to clean it. Give extra attention to the magnet on the impeller. Even one grain of sand in the gap between the impeller and the housing will jam it.