Do not guess at media
Tank appearance alone does not establish media type, remaining capacity or suitable replacement.
A carbon-treatment system is a combination of media, vessel, distribution components, control valve or backwash arrangement, piping and the facility’s operating practices. The right maintenance discussion looks at that system as a whole.

Equipment identification: record tanks, control valves and visible treatment stages.
Operating observations: note any pressure/flow observations, alarms, bypass position or maintenance schedule.
Water-quality context: preserve available test results and describe the operational concern without assuming the root cause.
Service history: gather invoices, manufacturer materials and any known work dates.
Tank appearance alone does not establish media type, remaining capacity or suitable replacement.
Unfamiliar valve settings or bypasses can affect water supply and equipment operation.
Performance depends on the system design, incoming water and the relevant service scope.
Photos, labels, history and facility needs make the next conversation more productive.