Problem with carbon is the expense if you change it out properly. Another
problem is if left in too long, when the carbon has absorbed all it can, it
starts leaching out toxins. It can hamper good bacterial growth both
initially, by absorbing materials needed by the bacteria and then later when
you change out the carbon, because bacteria will grow on the carbon so you
remove a chunck of your bacteria. Running carbon all the time presents some
problems as well from dosing medications and if you happen to have live
plants can also absorb water colum ferterilizers.

In general, use carbon only when removing medication you have placed in the
tank.

"JB" wrote in message
ps.com...
I ahve the standard Whipser HOB filter and have been using the filters
with carbon.. I recently discovered a site that said you should remove
the carbon to keep beneficial bacteria going through the filter...

Is this true?