Charcoal Filter on Holding Tank?

[Sweet As]

hi all,
I have heard some boats have an inline charcoal filter installed in the holding tank air vent line. I haven't one of these on our Bav36, nor do we particularly have an odour problem. Just wondering whether others have installed such a device and how effective they have found it to be?

[njsail]

@Sweet - I'm not sure what vent line set up you have but on my Bav ocean 40 the vent is a one inch hose that snakes along for several feet aft to vent behind the center cockpit just under the starboard rail.  On the rare occasion iI didn't catch the fact the tank is full and guests are aboard it has overflowed through the vent.  If you had a filter in there the filter would be fun to clean (not).  I would just pump out and shoot the pump out hose water back throughthe vent hole to clean it.  It is an easy fix for those rare times.  My last boat was an island packet and that had a permenant stainless  screen fixture over the vent hole.  I've heard many folks moan about how much fun that screen is to clean when the tank overflowed.   There are pros and cons to each design feature.