Originally Posted by Angel079
I have clear water in all tanks and no carbon. If you have water issues then either you're overfeeding; not doing proper water exchanges or issues with your filter in general.
You have nutrition coming from your source water, your fish, their waste etc; whether you use add liquid ferts or not this will be filtered out to some extent and chances are great your plants will not thrive the way they could with carbon in that tank.
The whole "carbon gives crytal-clear water" argument was created by the carbon manufacturers. In an established healthy tank, (especially one with plants) the carbon does way more harm than good. For example, my power filter came with a carbon "cartridge" in a mesh bag. After a few months, I took the carbon out, and filled it with filter floss.
Now, I don't think I'll ever have to replace anything in the filter- just take the floss out, rinse it out, and put it back in. :) On the rare occasion that the biofilter mesh is filthy, I leave the mesh/floss cartridge in and rinse the biosponge instead. That way the floss holds bacteria to recolonize the bacterial sponge thingy.