A COUPLE WEEKS AGO MY PARROTS WERE GETTING (WHAT APPEARED TO BE THE BLACK VELVETY LOOKING SCUM THAT GETS ON THE PLANTS!) I TOOK OUT THE PLANTS, WASHED THEM REAL WELL AND CLEANED THE STONES IN THE TANK. ALL OF A SUDDEN THE DARK VELVETY LOOKING MASSES STARTING GOING AWAY AND WITHIN 3 DAYS MOST OF...