To determine this, take the ceramic element out of your filter casing and look to see if there are any cracks or holes. If there are, then please do not continue to use the element since there is a risk that pathogens can get through the ceramic and therefore into your drinking water. If there are not any cracks or similar defects, then you can continue to use the element. Use the measuring tool it was shipped with to check to see if the thickness of the ceramic is still suitable for use. To do this, place the tong-like tool so one arm is on each side of the ceramic. If it stays in place and doesn’t slip, then the thickness is OK. If it doesn’t stick in place, you need to replace your ceramic element.