Waste Tank Smell

[Kim Schoedel]

When we flush the head, or when we tack to an aggresive heal, these horrable smells are coming from the vent. The PO didn't use the boat much the past few years and the local marina guy recommended to do a good pump out then clear water with a product called Rid X. The theory being that the bottom of the tank is caked with old nasty stuff and the Rid X will eat its way into the cake and loosen it up. Do this, wait a week, pump out, do it again etc until the tank is clean.

Just wondering if I should try this method or just replace the tank. Any ideas or thoughts on this would be appreciated. BTW, no smells from the inside, just the vent and it is baaaaad!

 

[Shadowfax]

We have had that problem also. Rid X is used in septic tanks to break up solids so that they can flow into the drainage fields. It is a biological agent that “eats” the solids, so Rid X should work. You might also try vinegar. This will also break up solids and also the scale that forms on the hose and tank walls that will also hold smells. Vinegar is very effective, both are environmentally friendly. After you get a handle on the problem using regular head treatements available at your favorite RV or marine store should handle any wayward odors.

 

[Kim Schoedel]

Thanks Paul, I hadn't thought of vinegar. Did you use vinegar in yours?

BTW, the regular treatment stuff worked great on our past boat but it doesn't do squat for this smell.

 

[Chris Miller]

Vent hose...

Might also look into replacing the vent hose and possibly install a vent hose filter. It's on my winter project list.
Chris

 

[CaptnNero]

filter, fresh water

Might also look into replacing the vent hose and possibly install a vent hose filter. It's on my winter project list.
Chris

I used a cartidge filter on the last boat and it helped. Using fresh water for the intake seems to help. Recently we started using the shower wand for flush water so it's all fresh going in. Eventually I'll plumb in a check valve from the fresh water system.

I picked a small aquarium air pump and an air stone to install in the waste tank when we're at the slip. That is supposed to prevent the nasty smelling anerobic bacteria. There is a marine manufacturer that sells a similar design for a few hundred bucks.

With salt water intake the water that sits in the intake hose all week gets pretty bad. On the last boat I installed a t-valve so that we could pump air into that hose before we left the boat. That eliminates a lot of internal odor when we came back to the boat and operated the head.

 

[Shadowfax]

Thanks Paul, I hadn't thought of vinegar. Did you use vinegar in yours?

BTW, the regular treatment stuff worked great on our past boat but it doesn't do squat for this smell.

Kim

Yes I used vinegar and it removed so much scaling that it clogged the Y valve and I had to remove it to clear it. The regular treatment stuff will work after you have really cleaned the tank and hoses. I bought one of those cartridges Neal talked about and found that it wasn't worth the $35 it cost, or the time it took to install, I have removed it. It worked for a bit, but was nothing more then a band aid. It was nothing more then 2 foot of 3" sch. 40 filled with activated charcoal with a fitting in each end. Chris, save your money, buy more beer instead.

 

[CaptnNero]

roll you own

... I bought one of those cartridges Neal talked about and found that it wasn't worth the $35 it cost, or the time it took to install, I have removed it. It worked for a bit, but was nothing more then a band aid. It was nothing more then 2 foot of 3" sch. 40 filled with activated charcoal with a fitting in each end. Chris, save your money, buy more beer instead.

Paul, maybe you just didn't pay enough. Mine was $75 !

Yes, I agree it was pretty simply made for the money but I didn't find the installation complicated in my boat. I installed two clamps and removed a couple feet of small hose to slip the filter in.

I found you could easily make one from some aquarium store charcoal and a few hardware store fittings so that is why I didn't buy another one yet for the new boat.

I agree that the filter doesn't get to the heart of the matter. You really need to somehow reduce the generation in the tank. This year it's been convenient to do a weekly free pump out so that has worked pretty well for us.

 

[Chris Miller]

Added comfort...

I have spent the last couple of years getting major smells out of both the water tanks and the waste tank (water tanks were stinky due to pink stuff). I have recently discovered that the vent hose is just regular water hose- which I don't really have an issue with, except that it's about 8-9 years old, and I'm guessing has some stinky-ness in it. I figure that with a clean tank and new hose, that a filter (thanks for the suggestions, I'll just make one!) will be added help. One more person to chat with at boat show (the raritan folks ) to see if they have any more advice!
Great advice and good topic!
Thanks,
Chris

 

[Shadowfax]

< Paul, maybe you just didn't pay enough. Mine was $75 ! >

Neal, I feel much better now.

 

[CaptnNero]

vent hose upgrade

...I have recently discovered that the vent hose is just regular water hose- which I don't really have an issue with, except that it's about 8-9 years old, and I'm guessing has some stinky-ness in it....

That's a good point Chris. While crawling in the starboard locker I noticed that the vent hose is starting to provide some odor. I'll probably put in the Odorsafe stuff there also instead of just the reinforced transparent stuff.

 

[u079721]

This topic sure does come up a lot. One thing that experts such as Peggy Hall have suggested is that you can keep odor down if the contents of the tank are well oxygenated to prevent generation of the stinky type of annerobic bacteria (apparently the aerobic bacteria are the good guys here). The problem with doing that is that it requires a large vent hose (I think she suggests 1.0 to 1.5 inches!) and a short run to the vent, neither of which were easy in my case. She also suggests that you never leave waste in the hose as that is a prime location for the generation of annerobic bacteria. And of course the problem with that is how much quicker your holding tank fills up if you flush well with each use. Note that if you are trying to get the aerobic bacteria to grow then you do NOT add formaldehyde type holding tank treatments, as those kill everything.

But there is a product that really seemed to help in our case - Odorlos. As near as I can tell this is just a fairly concentrated solution of sodium nitrate (or maybe nitrite) which acts as an oxygen source for the bacteria. I tried it a couple of seasons ago, and it really did help. What we found to be most effective was to add a capful (1 or 2 oz) with each use, into the bowl.

YMMV but I have several friends who have tried it and now swear by it. And the good thing is that it is fairly cheap to give it a try. Just be sure that you start with a well rinsed tank to get rid of any hold holding tank treatment.

 

[CaptnNero]

cross ventilation ?

This topic sure does come up a lot. One thing that experts such as Peggy Hall have suggested is that you can keep odor down if the contents of the tank are well oxygenated to prevent generation of the stinky type of annerobic bacteria (apparently the aerobic bacteria are the good guys here). ...

That reminds me of another recommendation that I've heard is to cross-ventilate. That means that you have two vents on opposite sides of the tank. I don't know where you're supposed to route that second vent exit but it's going to involve some scheming. In the end you could end of with two sources of odor venting I suppose.

 

[dcoyle]

I like the idea of cleaning tank with vinegar. How much vinegar should be used and is it white vinegar?

 

[Shadowfax]

I toss in a gallon. Yes white is fine, the cheaper the better. Pump some through the head and leave it in the hoses

 

[hcpookie]

Something to consider...

Question: Does vinegar react or counter-act the biological septic tank treatment enzyme stuff?

My waste tank installation included one of those maintenance hatches. If you don't already have one, I strongly recommend installing one. Get a big one, and you will be able to insert a garden hose sprayer and hose out the inside during pump-out. Mine is a 6" hatch, but I think an 8" hatch would be better.

Typically, pump-out will go something like this:

1. Normal Pump-out
2. Rinse the tank, pump out again.
3. Rinse again, pump out again.

I have had fantastic results, and the build-up is completely removed every time. The tank is absolutely clean after I'm done.

Obviously, I use an old leaky garden hose sprayer that I'm not worried about losing. Yes, and I wash my hands after I'm done

 

[hcpookie]

That reminds me of another recommendation that I've heard is to cross-ventilate. That means that you have two vents on opposite sides of the tank. I don't know where you're supposed to route that second vent exit but it's going to involve some scheming. In the end you could end of with two sources of odor venting I suppose.

The way I understand cross-ventilation is that on one side of the boat is the "intake vent" which faces to the front, and is placed closer to the front of the tank than the rear. Then the "exit vent" is placed on the opposite side, or at least downwind, and is located in the rear of the tank.

Supposedly, this creates a draft which purges faster than a single vent.

 

[u079721]

Question: Does vinegar react or counter-act the biological septic tank treatment enzyme stuff?

If you use enough vinegar is sure will, as it will lower the pH to the point where nothing can live in the solution. But it's not really a problem, as what you would do is run vinegar though the system, let it sit for awhile as usual to do the job (overnight is what lots of folks do), then flush the system with lots of fresh water. You can then add the biological attach stuff such as KO or whatever you use to encourage break down of new waste.

Isn't all this boating stuff glamorous!

 

[Chris Miller]

Boats and Dogs...

Talking about boats is like talking about dogs...
It always ends up about poo:thepaw:

 

[Frank Langer]

Is there a risk that cutting a porthole into the waste tank, even if bedded in 4200, and using a washer/ring for the opening, will allow some odour to escape. My holding tank is below the v-berth--the last place I would like the odour escaping.
Frank.

 

[hcpookie]

Yeah that's exactly where mine is. The ones that are available are intended specifically for waste tanks. I forget the brand name, I can look it up later if no one else posts. Mine was in fact part of the tank conversion kit, I forget the brand name but it was from the same company that makes the tanks, and I bought it at West Marine. I've seen the portholes in Boater's World as well.

They have an O-ring gasket and locks around the perimeter - not just screw threads, but actual locking "lugs" that engage, then slide about 3/8" until they seat.