What the difference in carbon?
Like I have seen small ones, long ones and slightly gray ones?
What I would like to know is what is the difference between them all or do they all do the same thing?
I have to order all mine online as the closest shops to me are over 1hr away and charge way to much.
Can't answer your question but I will say carbon is not a necessity unless you are removing meds or something from the water. If you have plants & add ferts the carbon can actually remove the ferts from the water which defeats the purpose of adding them. I've removed all carbon from my tanks.