Holding Tank Vent Line Filter ??

[Jim Vincent]

I've just read through many articles in this forum about holding tank vents and how tanks need oxygen. I hav'nt seen any discussion about filters in the vent line, (i have one, factory installed, i presume, it's about the size of a soda can) i noticed after buying the boat and using the head just a couple of times, waste water was dripping out of the vent. i pumped the tank and refilled with fresh water several times, the last right up to,(with water in sight)the suction port on deck and noticed the vent was still just barely dripping water. i was told, by a reputable marine sanitation business that once these filters get wet,...(tank overflow???) they become clogged. he suggested getting rid of the filter, which i'm doing, especially now that i've read about tanks needing oxygen. anyone else had any experience with these vent line filters???

[Mark Johnson]

I installed the vent filters on my Catalina 42 because every time the head was flushed it would GAG you. The filters seemed to work for that problem, but that stink was still in the tanks. Don't overflow the tank you will clog the filter. According to Peggy most holding tanks just don't get enough air so the good bacteria can't work to eliminate the odors.MPJ

[Peggie Hall/Head Mistress]

Filters do nothing to prevent or eliminate odor...they just trap it--but usually only most of it, not all. They're expensive...about $50 each...good for only a season at most--IF they don't get wet. We don't like 'em for the above reasons, plus they actually help to create the very problem they're intended to solve. If you're gonna spend that kind of money, you might as well spend it on modifications--if they're even necessary--to the system to make a filter unnecessary.

[Vito Ciaravino]

Pleaselet me know where this filter is located.ThanksEmail VCMS@aol.com

[Jim Vincent]

mine was in the vent line, directly behind and to the right of the main electrical panel at the nav station. unscrew the panel, pull it down, and there's the filter in plain view to the right.

[Bill Hufstader]

This is one person's experience; may not work for all; (1) I installed a Sea-Land brand holding tank level-alert indicator. In my case; an LED light that indicated 7/8th full. This will tell you when doom is near. (2)Install an odor filter in the vent line. About $60 discount and will last at least two seasons if you respect the aforementioned alert light and don't overflow through the filter. (3) Flush only with fresh water. In my case, I installed an 11 gal. Nauta-type water bladder under my stall shower seat. Good for a weekend for four. (4) Use only bacteria-type head treatment; no formaldehyde, bleach or bacteria-killers. These work best with oxygen so make sure your vent is operational. Augment flow with ventilation if possible. (5) I replaced the hose under my aft bunk with PVC pipe. Works very well.