The day anthracite is poured into the filter, it becomes a silent "goalkeeper", stopping silt, colloids and suspended solids around the clock. The most common question is: how long can this goalkeeper stay on duty? The answer is hidden in the daily operating details.
For normal tap water, circulating cooling water or ordinary industrial wastewater, if inlet turbidity stays between 10-50 NTU, filtration rate is 8-12 m/h, and back-wash intervals and intensity follow the book, anthracite will usually serve 2-3 years. Open the manhole every six months, top up the 1-2 cm layer lost during back-wash, and effluent turbidity can be kept ≤1 NTU.
When the raw water turns nasty-turbidity jumps above 100 NTU in the rainy season, or oil, sticky colloids, iron and manganese appear upstream-the goalkeeper tires quickly. Grains are rounded, pores clog, and pressure difference remains high even after back-wash. Service life then drops to 1-1.5 years or less.
To give anthracite a longer career, remember three rules:
Stop the "big stuff" ahead-install settling or fine screens;
Don't back-wash too hard; combined air-water wash at ~15 L/(m²·s) is just right;
Sample every quarter: if mean grain size wear is <30 % and breakage <5 %, you can keep using it with confidence.
The same bag of anthracite may last one year for some and four years for others. The difference lies not in the media, but in daily maintenance. Treat water quality, back-wash and inspection with care, and the black grains will stay with you for three quiet springs.
https://www.naturecarbon.com/anthracite-filter-media/
