I have not run carbon in either of my tanks should I?
1 is a 45 w/ shrooms anenomes polyps and sm fish 2nd is 125 w fish and shroom..tanks been up 2 yrs
It's good to have a bag of carbon sealed in an airtight container just in case of a chemical mishap. It's also good for removing the yellow from algae that slowly builds up over time.
When using it, force tank water through the carbon for 48 hours and then discard it.
Just my opinions of course
What is the reason for discarding after 48 hours? Also, are there any setups where using carbon on a regular basis would be recommended? (for instance, systems without a skimmer, or heavy FOWLR systems, etc)
In my experience carbon is not longer useful after about 48 hours.
A tank with a lot of softies or Caulerpa will benefit from running GAC once a month or more.