Cloverleaf sludge answer is a unique blend of beneficial bacteria to convert and remove sludge from the pond and filter system its perfect for use after using cloverleaf blanket answerr the accumulation of sludge within a pond or filter system means far more than an unhealthy sight when such deposits will not only erode important saturated oxygen levels but also become a detrimental breeding ground for nasty pathogenic bacteriar using natures natural range of bacteria cloverleafs sludge an