Translations:AY Honors/Fishes/Answer Key/48/en
From Pathfinder Wiki
Aquaria kept by hobbyists often do not have the requisite populations of bacteria needed to detoxify nitrogen waste from tank inhabitants. This problem is most often addressed through two filtration solutions: Activated carbon filters absorb nitrogen compounds and other toxins from the water, while biological filters provide a medium specially designed for colonization by the desired nitrifying bacteria. Activated carbon and other substances, such as ammonia absorbing resins, will stop working when their pores get full, so these components have to be replaced with fresh stocks constantly.
