Why is it that people dont use COAL? And when you guys say biological filter how do u determine its biologal filter vs. michanical ? ect.? im just a little confused
by coal you mean carbon. carbon is not necessary for a healthy tank, think of it as a sponge that soaks up impurities. It is beneficial when you need to remove medications etc. this is chemical filtration. mechanical filtration is filter floss. Bio- filtration is MOST important, bacteria colonises all over every surfas in your tank/filter and converts ammonia to nitrites, then to nitrates which you remove with waterchanges. if you have a good pre filter (mechanical) and a ton of media (biological) your good to go. another good alternative to carbon is purigen, you should look into it.