Filter media
Activated carbon
Best used as a tool for a specific job rather than as a permanent fixture. Its most valuable use is removing medication at the end of a treatment course — and its most common mistake is leaving it in the filter while dosing one.
Short answer
A highly porous adsorbent that removes dissolved organics, tannins, odours and medication. It does nothing for ammonia, nitrite or nitrate, and it exhausts within weeks.
What it does
- Adsorbs dissolved organic compounds, tannins and many medications
Strengths and where it fits
Strengths
- Clears tannin staining
- Removes medication after treatment
- Removes odours and some pollutants after an accident
Good fit for
- Post-treatment clean-up
- Clearing tannins
- Emergency response to a contaminant
Limitations and where it is the wrong choice
Limitations
- No effect on ammonia, nitrite or nitrate
- Exhausted within two to four weeks
- Removes medication you are trying to use
- May remove some trace fertiliser elements in a planted tank
Poor fit for
- Permanent use in a planted tank
- Any tank being medicated