[C320-list] SeaLand SaniGuard Holding Tank Vent Filter

[Joseph A Tamucci]

I just installed a SeaLand SaniGuard Holding Tank Vent Filter and thought
I’d share this with you.  Andante also has had the recurring obnoxious
aromas emanating from the holding tank vent when the head is flushed.  This
spring I decided to address the problem before the sailing season.  I saw
the SeaLand SaniGuard Holding Tank Vent Filter advertised for $70 at West
Marine and thought I’d give it a try.  Denvender also has it at this price.
This sealed carbon filter  is about 2 ft long and installs in the head vent
hose line.
 
I thought it would be an easy install: just cut the line and install the
filter just above the holding tank.  Not so fast.  The filter must be
installed above the water level of the tank and the vent hose must not have
any dips in it so no sewage backs up in the system if the tank is overfilled
or when the boat heels.  The diameter of the filter is about 3 inches and
there is not enough space between the top of the tank and seat to fit it.
The filter requires replacement every season so I wanted to install it where
I could replace it easily.  
 
I decided to install the filter in the aft cabin hanging locker on the
removable back panel.  Since the filter is a fully sealed unit there should
be no issue with smells.  I thought I could cut the existing vent hose and
just connect the original portion of the vent hose from the hull opening
vent to one side of the filter and run a new hose from the other side of the
vent filter to the holding tank.  This would save me the hassle of trying to
get at the hose connection at the thru hull vent.   The first problem I
encountered was the existing vent hose is ¾ inch and the filter I purchased
has 5/8 inch hose  fittings.  I think there is another filter model that has
¾ inch connectors but West marine only had this model in stock and I didn’t
realize the hose was ¾ inches.  
 
Given that issue and the fact that the original hose was coated and smelly
inside anyway, I decided to go ahead and replace all the hose with new 5/8
inch hose and do it right.  I took the advice of another 320 member post and
unscrewed the  medicine cabinet (did not remove it) to gain access to the
thru hull vent hose fitting.  I removed the back panel of the hanging
locker.  It is in fact a tight squeeze and reach to get at the fitting but
you can do it this way.  After loosening the hose clamp (no easy effort with
the limited access) I could not pull the ¾ inch hose off the fitting.  I
finally slit the hose at the fitting and discovered that the actual vent
connector is ½ inch.  Catalina kluged it by using a ½ hose piece and
slipping the ¾ inch vent hose over it to make the connection!  Since I had
5/8 inch, still too big to fit the vent connector,  I likewise forced the ½
inch tube piece into the new 5/8  hose and with much grunting and some
Vaseline (I know what you’re thinking), forced the hose far enough into the
thru hull connector to clamp it on.  I ran the hose over the space above the
panel in the locker and mounted the filter diagonally screwed to the back of
the panel.  I cut a slot in the panel and ran a hose from the other side of
the filter to the holding tank vent connector and was able to force (again
with Vaseline) the 5/8 inch hose over the ¾ inch holding tank connector.
All connections were clamped.
 
This configuration keeps the assembly well above the holding tank and there
are no dips in the hose and allows me to replace the filter from the hanging
locker.  Total hose used was about 12 ft.
 
Hopefully the new hose and a filter will rid Andante of the embarrassment
when the head is flushed.  I’ll let you all know how the filter works.
 
Joe Tamucci   Andante #619