Hi can anyone advise me I've put some green slate pebbles on avwaterfall I've built on the pond altho I rinsed the stone I now have a cloudy pond I've got an hozelock easyclear 3000 filter but this doesn't seem to be clearing the silt away the foam filters seem as if they are letting the silt threw would putting Some fine cloth or something in between the filters help clear my pond of will it harm my filter