Filter Questions

[fyrefaerye]

I am setting up my new 36 gal tank that came with a quiet flow 30. I've read that it may not be enough filter for my tank. So just to be safe I went and bought a quiet flow 10, but I haven't installed it yet. I literally just set up the 30 today. Will the 30 be enough for my tank or should I install the secondary filter??
 
Also. I read that the carbon cartridges are not exactly ideal filter media. Should I modify the filter and use different medium??

 

[NeonBlueLeon]

To be honest, filtration should be lightly based on the kind of fish you're stocking in addition to your tank size.  A quiet flow 30 in a 36 gallon may be okay unless you stock really messy fish (i.e. goldfish).
 
What carbon does is absorb organic molecules that tend to cloud up the water.  It does not absorb ammonia, nitrites, or nitrates.  A substantial amount of beneficial bacteria is contained in your filter media, so having additional surface area in your filter will allow more space for bacteria to grow. 
 
Carbon needs to be replaced every month or so (meaning you're removing the bacteria that has grown on the carbon cartridge), which is probably why some people say it is not "ideal."  In my HOB filters that only have a carbon cartridge, I add sponges in the extra space in the filter to provide surface area for bacteria to grow.  That way, when I change my carbon cartridge every month, I don't have to worry about a lack of beneficial bacteria.
 
Note that beneficial bacteria also grow on your substrate and decorations.  The bacteria basically grow on all of the surface area in your tank, with a bulk portion being in the filter media.  If you've got decorations and sand/gravel substrate, you should be fine.