Holding Tank Vent Filter Size?

[codingparadox]

Every time we flush/pump the head, we get a nice whiff of holding tank fumes. Seems like it's time to change out the vent filter. Anyone know what size it is? Next time I'm out there I can go digging, just wondering if anyone has ordered one of these recently and knows what to buy, so we can get an odorless next journey.

[gmc60]

I was told to change it once a year there all about the same size ?

[Gugi47]

Originally Posted by codingparadox

Every time we flush/pump the head, we get a nice whiff of holding tank fumes. Seems like it's time to change out the vent filter. Anyone know what size it is? Next time I'm out there I can go digging, just wondering if anyone has ordered one of these recently and knows what to buy, so we can get an odorless next journey.

Would be a good idea to use some of this:
https://www.ebay.com/itm/Walex-RV-Ca...sid=m570.l1313

[codingparadox]

Yeah, when we pump out next I'm going to start a regimen of holding tank probiotics and such, but I want to address the probably-not-replaced-in-19-years vent filter at teh same time.

[PJHoffnet]

Also make sure the line from the filter to your overboard vent - when I replaced my filter this year I found the clam shell cover for the vent thru hull was salt encrusted. I used a coat hanger and air (after soaking with vinegar) to get it clear.

[codingparadox]

Got out to the boat today and checked it out. So, there's actually no vent filter, just a vent line that goes up to a through-hull! I could just splice a vent filter in, but I think the real answer is just fixing the smell in there for now and seeing if that's enough long-term.

[Gugi47]

If your line is 5/8, here is what you need to buy:
https://www.ebay.com/itm/Voker-Holdi...LH_TitleDesc=0

[rwc]

Is the odor in the head or on deck?
If on deck, reducing the odor in the tank should fix it. If in the head, your vent line may be blocked, possibly by a corroded vent head, causing the increase in pressure in the holding tank to force gas back down the line into the head, instead of out the vent.

[codingparadox]

It's on deck. Smells fine in the head.

We've gotten some stuff to put in the tank to break everything down and make the smell go away. Thanks!!

[dannyrayz]

Clean the tank out good and don't poop in it if possible...bag it!

[shrew]

Originally Posted by dannyrayz

clean the tank out good and don't poop in it if possible...bag it!

lmfao!!!!!!

[shrew]

In order to pump contents into the holding tank, the air needs to be displaced. The air is displaced through the tank vent. The air in the holding tank gets funky as a result of what is being dumped back there. You can reduce air by rotating a large volume of air thorugh the tank, but the vent size and lack of active air movement (fan) reduces the effectiveness.

1) Pump out frequently. Never let contents sit for more than 5 days (we pump out every Sunday before we go home for the weekend).

2) Use holding tank chemicals to break down material and reduce odors. Use more than expected.

3) flush the tank out with freshwater periodically.

4) Install a holding tank vent filter. (Yes, locate a spot at least 1 foot above the top of the tank. Cut the line and insert the filter.

[MoonRiver]

Just last weekend we had an issue with our black water system. When we flushed the toilet brownish/ orange water came out around the pump-out port and the macerator overboard discharge port. When we tried to pump-out nothing came out and water would not go in.
I ran a snake down into to the tank but found nothing blocking. I blew air down through the holding tank vent, but nothing moved. What I found was the through hull port was completely clogged with crap. I chiseled it out and cleaned and scraped the screen. Put it all back together and everything worked perfectly.

Moral of the story "don't accuse people of flushing BAD things down the toilet until you troubleshoot". My guess is previous owners had a few too many totally full holding tanks that blew out the vent port and then dried.