Cleaning Black Tank

I flush out my black tank a couple times a season by running water thru the pump out. I also rinse out tank by removing the sealand tank watch cover and add laundry detergent. My wife and I have also adopted a no paper in the head policy. My question is, is there any risk of breaking off the longest probe on the tank watch by putting ice in the holding tank and taking the boat out for a ride . Any and all comments are appreciated
Kevin
2006 Nordic Tug

Why would you need to use ice if you wash your tank that often?

Seriously? You bag your dirty TP!? Why?

Don't think I'd do it.

If you're having smell issues, I think the first thing I'd check out is the vent for the tank. From what I've learned if undersized all sorts of smelly things happen.

Btw we have cleaned ours with two gallons of white vinegar and some water. Leave in for a day or so then flush out.

96kpmjmm said:

I flush out my black tank a couple times a season by running water thru the pump out. I also rinse out tank by removing the sealand tank watch cover and add laundry detergent. My wife and I have also adopted a no paper in the head policy. My question is, is there any risk of breaking off the longest probe on the tank watch by putting ice in the holding tank and taking the boat out for a ride . Any and all comments are appreciated
Kevin
2006 Nordic Tug

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I don't know about the ice, but it would really suck to damage the probe.

I guess I am confused by the issue. You do through a lot of trouble to accomplish something, I just don't know what that is. Is there a problem that you have that needs resolution?

Removing the sealand cover to clean out the tank seems like a HUGE pain, yet you only flush the tank a couple times a season? You have quit using TP which is literally another pain in the ass, yet you only flush the tank a couple times a season?

Help us help you and answer some questions first (and if I am not mistaken some of these Peggy would ask as well)

- Fresh or Raw water flush?
- What type of head?
- What type of tank treatment are you using right now?
- What problems are you noticing that prompt your question?
- What prompted you to go not use TP in the head and did that change in use make a difference?

Capt Bill. My view is the less i put in the head the less potential problems i could have. it is just my wife and i and we empty daily. We don't sea it as a big deal( we do the same thing in our motorhome )

Dhays, We are having no problems with our system. As for removing tank watch cover it is very easy, 2 seconds. On my boat it is as easy as checking my oil
It a vaccum flush system fresh water. I am using sealand tank deodorant. As for other preventive things that i do. We always pump out or dump at a 1/2 or 3/4 of a tank. Soak and brush off probes on tank watch every season . Remove filter and blow vent line out. And when pumping out, turn off water and have wife step on toilet peddle so IF vent is clogged the tank would still get air. As for putting ice in the tank this is a copy and paste from peggy. It sounds like a good idea and its cheap, but i just don't want to break the longer probe. I have copied and paste below from another thread peggy had posted. My only concern is the ice hitting the probe.
Thank you for taking the time to respond.
Kevin

Human body waste contains animals fats which can build up on tank walls and clog
tank gauge senders. So every year or two--or any time you’re preparing the boat for winter or other extended layup--it’s a good idea to clean out the tank. Follow the above instructions, then fill the tank with clean water and put a gallon (2 gallons if the tank is 50 gallons or larger) of liquid Tide, Wisk or any heavy duty liquid detergent and about 10 lbs of ice cubes into the tank via the deck pumpout fitting (not down the toilet!). Use “homemade” ice, not bagged ice...”homemade” cubes are larger and harder, so they last a lot longer. Go sailing and tack a lot, or go out on a day when seas are bit rough if you’re a power boat. Then, if you can, let it sit overnight. Pump out and also run some of the detergent solution through any macerator pump and related plumbing. Fill tank again with clean fresh water...pump out or dump and
rinse out again.

Thanks for the info Kevin.

If it was me, I would get rid of the vent filter. The filter makes it impossible to back flush the vent without removing the filter. I like to back flush the vent and rinse out the tank every time I empty it. It doesn't take long and is a whole lot easier and cleaner than opening up the tank to clean by hand. I typically rinse twice after pumping out. I just put water into the tank from the pump out opening with a hose. I pump it and and repeat. On my new boat, the PO never did this obviously. I have been rinsing the tank 3-4 times each pump out (only three so far) and each rinse I get more sludge up from the bottom of the tank. I figure eventually, the tank will rinse pretty clean. My situation is much different than yours however as my boat never sits in an off season.

I recall reading Peggy's ice suggestion but don't know about the effect on the longest tank watch probe.

Since you can take the tank watch cover off, what does the inside of the tank look like after you have rinsed it? If the inspection is difficult use a bore scope.

If you still want to use ice, make a temporary cover for the tank watch cover and go for it. I'm not sure how clean a holding tank needs to be though?

1) There's no need to "bag" toilet paper. That's disgusting. We have been using "Scotts" brand single ply toilet paper in two different boats since 2003 with no problems.


2) Get rid of the vent filter. They are more trouble than they are worth and actually restrict the flow of air.


3) If you have an inspection cover, forget the ice and get a toilet brush or scraper and clean the tank if you feel it's necessary. A hose with a nozzle to create high pressure will also work.

Dhays
Thank you for taking the time to respond. When you back flush the vent I assume all you are doing is shooting water into the outside vent then into tank making sure it is not clogged? Am i correct?
Second, is a filter on the vent really necessary?

WesK
Sorry to have disgusted you with our paper policy.

All thank you for taking the time to respond to my question, am still new to this and with having only one head on board i want to properly maintain it

Capt.Bill11 said:

Why would you need to use ice if you wash your tank that often?

Seriously? You bag your dirty TP!? Why?

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Bill

You must admit, these types of threads keep us awake and coming back!

There really is no reason not put TP in a properly functioning marine head and holding tank.

But if it makes you feel better to take your poop paper for a walk, knock yourselves out.

Of course you could save yourselves the trouble and get a bidet attachment for the head.

sunchaser said:

Bill

You must admit, these types of threads keep us awake and coming back!

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yep....more thrills about personal hygiene stuff than a good special ops war movie.....

I need a popcorn maker aboard....:

96kpmjmm said:

Dhays
Thank you for taking the time to respond. When you back flush the vent I assume all you are doing is shooting water into the outside vent then into tank making sure it is not clogged? Am i correct?
Second, is a filter on the vent really necessary?

All thank you for taking the time to respond to my question, am still new to this and with having only one head on board i want to properly maintain it

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96, In my own simple mind, I see two general approaches to managing a holding tank. One is to try and kill off anything in the tank, mask the smell, and then add a vent filter (usually activated carbon) to try and capture any smells that escape from the tank when more waste it added.

A second approach, one that I take, is to try and nurture the aerobic bacteria in the holding tank that actually break down waste. These bacteria don't produce foul smelling gas. These critters need enough oxygen however to thrive. Anaerobic bacteria will also break down waste and don't need much oxygen to do it but produce the nasty smells in the process. There are different holding tank treatments for this method that try to encourage aerobic bacteria growth in the holding tank.

One problem with a vent filter is that it, as WesK noted, reduces the amount of air exchange through the vent. This reduces the amount of oxygen available in the tank for those aerobic bacteria. Secondly as I mentioned earlier, it makes it difficult to back flush your vent line at the time of pumping out the holding tank. So to answer one of your questions, I don't think a vent filter is necessary at all and can actually make this second approach to holding tank management more difficult.

The procedure for back flushing the vent is easy when there is no vent in the line. While you are pumping out the holding tank, air is rushing into the tank via the vent line to replace the volume of liquids that you are evacuating. If you direct a stream of water from the hose over the opening to the vent while you are doing this, water will be sucked back down the vent line. Since the vent line usually has a much smaller diameter than the holding tank pump out, the water goes in a pretty high speed flushing the line nicely. This will help keep the vent clear of any waste that may have splashed up to the vent opening and dried, or if you fail to empty the tank in time and the waste level reaches the level of the vent.

So my typical procedure for emptying the tank is to first pump the tank empty. I then put as much water back into the tank with a hose through the waste opening as my patience allows and then pump out the tank again. While pumping this time, me or my helper will direct the hose stream over the opening of the vent. You generally will hear the water being sucked into the vent. Once the tank is empty a second time I will repeat that same process. If you clean your tank well now, and then always rinse it twice when emptying it in the future, you shouldn't really ever have to clean the tank again IMHO.

It is often hard to get adequate air exchange in a holding tank. On some boats it is next to impossible (like my old Catalina 36). It also takes a certain amount of thought as to what is actually happening in the process. When the process starts to fail, you get bad odors coming out the vent when the head is flushed. I think this is why so many boaters give up and go with the "kill them all" holding tank treatments and install vent filters. Both approaches work, find the one that works for you.

As for not putting TP in the head, I wouldn't worry about it. Use cheap single ply TP, or if you are concerned spend the premium for the special purpose single ply that West Marine and others sell. Either way, the TP breaks down very quickly in the holding tank and won't give you any problems. Just don't flush anything else down the head.

T m i

Dave
Thank you very much.
Kevin

A few comments...first to dHays
It appears you've read my books (at least one of 'em anyway)!

The procedure for back flushing the vent is easy when there is no vent in the line. While you are pumping out the holding tank, air is rushing into the tank via the vent line to replace the volume of liquids that you are evacuating. If you direct a stream of water from the hose over the opening to the vent while you are doing this, water will be sucked back down the vent line.

Or you can do it the easy way: replace the "vent" thru-hull with an open bulkhead thru-hull that you can stick a hose nozzle against to backflush the vent line every time you wash the boat. Any insect that finds its way in will just take a water slide ride into the tank.

Boat builders use the same vent thru-hulls for all tanks--fuel, water, and waste. They're actually designed with spark arresters for use on fuel tanks, and have tiny openings to keep sea water out of the fuel or water. But the very things that make 'em suitable for water and fuel make 'em the wrong choice for waste tank vents because the tiny openings don't allow the exchange of air needed to keep the tank aerobic. An open thru-hull may let sea water in, but a little water won't matter in sewage.


Next to 96kpmjmm
We are having no problems with our system. As for removing tank watch cover it is very easy, 2 seconds.

There should be a rubber o-ring on the cap, which is necessary to seal it. Repeatly removing the cap can damage it. I suggest you replace it.

It a vaccum flush system fresh water.

That explains why you're reluctant to flush TP. Too little water going through a VacuFlush will let solids and TP build up in the pump, creating a clog. Peddle should stay down at least 3 full seconds after urination, 7-10 seconds after solids and/or TP...It's also advisable to flush a full bowl of clean water through once a day if you're a liveaboard, at the end of each weekend if you're not. If you follow that regimen, you'll have no trouble flushing TP.

I am using sealand tank deodorant.

That's why you need a filter in the vent line. Replacing your vent thru-hull as I described in my comments above to DHays and use a tank product called Odorlos Odorlos according to directions (which is the hard part for most people) and you won't need a filter. Odorlos is a non-toxic product that works WITH nature instead of trying to kill it...the active ingredient is nitrates, which promote oxygen release from the waste in the tank, helping to keep aerobic. YOu can find it WM, but it's more widely available at RV supply stores for a LOT lower price!

As for other preventive things that i do. We always pump out or dump at a 1/2 or 3/4 of a tank. Soak and brush off probes on tank watch every season

Replace the TankWatch senders with the Profile Profile Tank Monitors sender that goes on the outside of the tank and you'll never have to do that again. It will work with the existing TankWatch wiring. We just had a long thread on tank level indicators that should answer most of your questions about doing this.

And when pumping out, turn off water and have wife step on toilet peddle so IF vent is clogged the tank would still get air.

Let your wife take a break 'cuz there's no way the pumpout can pull air through 4 duckbill valves, the vacuum tank and the backflow preventer in the pedestal assembly.

As for putting ice in the tank this is a copy and paste from peggy.

And if TankWatch senders were too fragile to withstand being bumped by a little ice, they couldn't survive some solid waste.

I absolutely hate it when someone that actually knows about a subject and is acknowledged as being THE expert on that particular subject by all of the most knowledgeable professional people in the entire boating industry puts up a response to a question. I mean, it just stifles conversation . love you Peg.

Peggy, I have read your book and have been reading your posts in forums for a long time.

When I replied to Kevin about the vent it suddenly occurred to me that on my new boat, I don't know if there is a vent filter. I am guessing there is. The vent is also smaller than I would like it as is the vent line I imagine. Yet another thing I need to find out about this boat.

Thank you Peggy and Dhays for taking the time to respond to my question with a detailed response.
Kevin

96kpmjmm said:

Thank you Peggy and Dhays for taking the time to respond to my question with a detailed response.
Kevin

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And Peggy even gives you accurate and complete information.

After having been boarded by the GKs for the weekend, and having to unclog the Vacuflush, I heartily agree with the 'HeadMistress' advice recommendations and information.

I was wondering about the filter. Seems the general opinion is to have NO filter, but have an anerobic tank to help digest the contents. Excellent idea.

Thanks for sharing ideas.

Who wants to take used TP for a walk anyway?!

Greetings,
Mr. 208. "...have an anerobic tank to help digest the contents." Not quite. You want an AEROBIC environment meaning WITH oxygen for the digestion to occur.

RT Firefly said:

Greetings,
Mr. 208. "...have an anerobic tank to help digest the contents." Not quite. You want an AEROBIC environment meaning WITH oxygen for the digestion to occur.

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Obviously I and 'aerobic' have never met!!!! Darned autocorrect. I get the intention. It is the details that need ironing out.

The big hassle with poisoning the tank contents is dumping.

If it goes to a big municipal system , the unused poison wont be a hassle,

BUT if you pump out in a remote location with a septic field , there is a chance that the poison will kill the good stuff in the septic system.

This can cause the field to flood with raw sewage , requiring the systems replacement.

Extra air is used on the big $$$ charter boats , as side by side,stern too, there is always an open port near a lower boats tank vent.

At $10K to $50K a week "outhouse" not what the guests expect.

A small aquarium sized air pump will do wonders to get rid of the stench.

Regarding tank vents of any size on smaller vessels....

I was lucky enough to have a marine engineering type with excellent quals send this. It somewhat reinforces my thoughts on smells in holding tanks and condensation in partially empty fuel tanks.....

"Where does (edited) the pressure differential comes from to create a flow in that little tube?

The air and fumes flow through the little tiny screen holes exactly the same as they do when fitted to a fuel tank.

When the tank fills, the nasty fumes goes out the vent, that is what it is for. When the tank is emptied, clean air goes in the vent, that is what it is for. The rest of the time there is no flow because there is no pressure differential to create a flow.

The holding tank vent could be a 3 inch pipe and it still would not aerate the tank sufficiently to keep it aerobic. An ideal system would use a vent fan to draw gases off the top of the tank and discharge them where the smell would not be noticed, and aeration would be supplied through a bubbler system in the tank. Thinking and telling someone that a (edited) small boat vent hose exchanges air to keep the tank aerobic is just plain (edited) incorrect."

I edited just a few words, no change in info passed.

I have no idea or care about microbes, etc. As a liveaboard, the turnover through pumpouts seemed to keep the problem at bay.

None of the boats around me in all the marinas through decades of active boating have ever given me a nasty wiff.

Even replacing dozens of those silly filter on Sea Rays back a decade ago...never once did it seem to matter unless the tank filled the filter from an overfilling.

The only smells I ever seem to really notice are the classic hose permeation smell and where spills have occurred and never cleaned up well.

The other issue sometimes is it isn't even the sanitary system...it is just a nasty bilge or shower sump issue.

Wouldn't a vacuflush system introduce enough air for aerobic bacteria?

Drake said:

Wouldn't a vacuflush system introduce enough air for aerobic bacteria?

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Good question...

Maybe any toilet that flushes enough bubbles in the pumping introduces enough oxygen.

I'm guessing it is not an easy nail to hit...so many variables, yet a few pretty easy to guess givens.

Looking at one particular system at a time...it probably could be figured out in short order...but to broadstoke all boats and their head/holding tank systems might not be too easy

FF said:

Extra air is used on the big $$$ charter boats , as side by side,stern too, there is always an open port near a lower boats tank vent.

At $10K to $50K a week "outhouse" not what the guests expect.

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You forgot a couple of zeros. Big $$$ charter boats start at $50,000 a week and rapidly move up to the hundreds of thousands of dollars per week range.

The last boat charter boat I was on chartered for $145,000 per week. And yes we did have a Head Hunter Tidal Wave system with air and chlorine injection.

But it's not that expensive to add air injection to your existing holding tank.

FF said:

A small aquarium sized air pump will do wonders to get rid of the stench.

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Capt.Bill11 said:

But it's not that expensive to add air injection to your existing holding tank.

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I can attest to the accuracy of Peggy's recommendations...

Last boat had a severe smell problem - after reading Peggy's book I started to explore the vent system - found a long convoluted vent hose path which I shortened & straightened. Then added a larger second vent on the opposite side w/ larger hose and straight thru hull - smell issue basically gone

Current mainship also has a significant smell issue - vent is LOOONG - SMALL and the thru hull is screened angle type that doesn't do much to aerate tank.
Unfortunately adding a vent and correcting the existing one is next to impossible due to the tank location and limited access.
I have added a simple home made bubbler that has made a huge difference - as Peggy states - the only drawback is you have to run it 24/7 which I almost do - we shut it down overnight and start it up early next AM - still seems to be effective
See the Holding Tank Aeration System link for details

Peggy - thank you for your thoughtful information.