I've had my aquarium running for 2 years, 29gallon with a Ehime canister filter running nothing but phos absorb and carbon. My question is how big of a difference does it make running the carbon vs running none.
Not much.
In fact, i used to run carbon 24/7 but now i'm experimenting with not running it at all for a couple weeks, then running it for several days, then not running it for a couple weeks, etc. I'm not 100% positive yet, but I think the coral does better without it.
imo, i think its smarter to run carbon on smaller tanks such as yours.
small tanks get mucked up way too easy and carbon will help keep them clean and healthy. prob dont have to run it constant but regularly would bea good idea.
It helps to run carbon, especially in smaller tanks like mentioned, but not necessary. I personally run it all the time. It can't hurt by being in there and can only help by removing toxins.