Gregcoyote
Aquarium Advice Addict
Jason M said:No all carbon has phosphate in it. Whether it be 1 of .3 ppm. Most carbon sold had a detectable reading after agitating it. Some not till later.
Not correct.
http://www.hallman.org/filter/gac.html
Good reading. Yes, SOME carbons are washed with Phosphoric acid, some are not. There are over 100 types of activated carbons, some for atmospheric use, some for water.