Leaving Carbon In Filter While Treating For Ich?

[frogluver]

I recently introduced a new fish to my tropical fish tank, and now all my fish have ich. The instructions on the ich medication read "Remove carbon from filter, add one drop per gallon daily until cured on all fish except those of the Tetra group. For Tetras- add one drop for every two gallons." Some of the fish are Tetra and it is a 20 gallon aquarium, so I added 10 drops and removed the carbon. The fish seem okay, however I am worried about the water while the carbon is out. How long until I can replace it?

 

[loraxchick]

carbon isnt really necessary unless removing meds or tannins. and it decreases in effectiveness over time. after your treatment for ich, do a large waterchange and replace the carbon...will remove the meds and give some surface area for bac. in the filter. and you can just leave that be until you need to remove more meds or tannins.
cheers