Holding tank cleaning?

I use typical holding tank chemicals readily available in marine stores, but whenever i use my vacuflush toilet, pretty bad smell comes out the vent line. The tank is regularly emptied at pumpout station in my marina and level is low in it although I do not know how much of the tank volume is unpumpable. The boat is 1980 with original holding tank. Is there a chemical out there that can be effectively used to pour into the tank with the fresh water to try and dissolve the accumulated deposits on the sides and the bottom of the tank? My hoses are new, and i do not have bad smell in the boat. it is just when vacuflush is used that it smells bad as it pushes the contents of the hoses and vacuflush tank into the holding tank. Would a quantity of ordinary bleach and fresh water dissolve the contents and improve the condition?

I would start with vinger and see how that works

Holding tanks should be at least nominally rinsed out after every pumpout or dumpout...thoroughly flushed out 2-4x year depending upon length of your season, and especially in preparation for winter or any other extended layup. It’s not hard to do, and all you need is water:

Pump out the tank, or dump it at sea. Then put enough water into the tank via the
deck pumpout--becasue that sends the water into the tank at the bottom to stir up any sludge and hold it in suspension so it can be pumped out--to cover the bottom to a depth of 4-6”... it can be fresh water at the dock or sea water using a washdown pump. Pump out or dump... repeat...repeat...repeat...till you’re pumping or dumping clean water.

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.

Chemical holding tank products are cheap, but they don't work and they're about an environmentally UNfriendly as it's possible for anything to be. I suggest you try a product called Odorlos. Odorlos The active ingredient is nitrates which help to promote oxygen release from the waste (oxygen is key to odor elimination). It's a lot more readily available --not to mention a lot less expensive--from RV supply stores than marine stores.

Vent line filters should only be used as a last resort because a) they actually help to create the problem they're sold to solve...and b) they're EXPENSIVE!

Pure pleasure said:

I would start with vinger and see how that works

Click to expand...

It won't do much if anything. Vinegar--distilled white vinegar, not cider--does a very good job of PREVENTING mineral buildup in hoses when applied on a schedule, but would take forever to dissolve it. However, his problem isn't mineral buildup, it's animal fats. Vinegar won't do a bit of good to clean that off the walls of the tank...nor will bleach, which should never be used in a sanitation system because it's destructive to rubber and breaks down hose resistance to odor permeation.

I use Unique Digest it in my holding tank and it liquefies everything in the tank so it all gets pumped out. It's available from Amazon, while using it the directions say not to rinse your holding tank out with dock water.


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That's certainly unique! Do they say why?

Take a look at Noflex. I'm hearing good things about it but I haven't tried it yet.
http://www.gemini-ltd.com/pdfs/TECH-DATA-14/T-FI-ZAA-004-Noflex-2013-Marine-Intro-rev3.pdf

Greetings,
Mr. B. Further to Ms. HM's excellent, as always, advice (although I seriously question her comments in the "Traveling Companion" thread) in post #4, above, another VERY good reason never to use bleach or a number of the commercial head treatments on the market in your holding tank is that bleach will kill the beneficial bacteria that you most definitely want to propagate in your tank.

If the deck pumpout tube goes to the bottom of the tank (which mine does, about 3/8"), how are you supposed to get ten lbs of bigger, homemade, ice cubes in through there?

I've used noflex digester for five or so years with no build up on the tank wall.

I've used Noflex for 2 seasons now, no head odors, but it hasn't cleaned off the sidewalls, or did it free up our tank sensor float.


Didn't actually notice we had any build-up on the tank sidewalls until just the other day...


It maybe COULD eventually clean the tank walls a bit, but I think that would take more treatement while only clean water is in the system... and I can't handle the downtime that would entail.


Looks to me like no way it could clean the uric acid crystalline build-up off the holding tank sensor. I just pulled and replaced that, and the whole bottom of the tube is completely encrusted. (This partly because that tube was actually slightly too long for that tank depth.) I'm told maybe soaking the sensor in muriatic or phosphoric acid may clean up the old sensor; we'll see.


With that as background... I'm not at all worried about the slight build-up on tank sidewalls. No odors, so no cares (generally speaking). Used KO for the many years preceding this Noflex experiment, seemed to work fine, too -- in that we've not had to deal with head odors. Don't know if it would clean sidewalls any better than Noflex or Odorlos or whatever...


-Chris

We have lived on the boat for 18 years when we leave for long periods of time, I spray clorox spray down the toilets and hose, have the tank pumped out. After 16 years had the toilet andhose changed out. We had no smell odor, the hose got clogged to a point it was hard to flush thru. New toilet and hose should last another 15+ years.

Some marinas have inslip pumpout equipment, every so often we'll stay at one of these, there is usually no rush to pumpout there so I'll pumpout and clean the tank. Our 45 Gal. tank has a 6" inspection/cleanout plate in the top, I'll bring a water hose with spray nozzle down to the tank and give it a good spraying, through the inspection cover hole, which really cleans it up inside, then pump out again, repeat if needed, and we are ready to go.
Same can be done at a non busy dock maybe with a nice tip for the attendant, as long as you have a cleanout port on the tank.

PS hold a rag over the hole while you are spraying the tank to keep the spray off of your face!

HeadMistress said:

repeat...repeat...repeat...till you’re pumping or dumping clean water.

Click to expand...

How can you tell? My ejection is below the waterline and all the hoses are solid, not clear.

Greetings,
Mr. Steve. That's what I was almost going to suggest to Mr. B. but I somehow got the impression that that would be WAAAY down his "list". We haven't needed to go that route yet but I would not hesitate to do so. I have a Hookah style dive compressor so smell would not enter into the picture given sufficient ventilation in and around the holding tank locker.

There are so many holding tank treatments out there and so many people that have their favorites. But if you have a problem that one day you favorite isn’t working “Try the Noflex”

For odors in the pipes and from the tank vent use as instructed on the bottle or web page

http://www.gemini-ltd.com/index.php?p=product&id=715

The smell from the vent will be gone on after the first use of the Noflex.

If you have the sludge problem --
Pump the tank out as much as possible and for every 20 liters of tank add about one oz of Noflex
Wash it down the toilet with enough water to fill the tank to 90 % full and leave it for 24 to 48 hours . (If you have vacuum flush toilets try not to get the powder on the rubber or ball)
If your tank sludge is more than 50 % of the tanks volume you may have to do this a second time.
Then use the Noflex on a routine basis once every couple of days to keep control of the smells and sludge.
If you do not have the luxury of time use a tablespoon every day (per person on board ) for a month and then cut it back once you see the tank walls cleaning up.

You do not have to rinse out your tank if you use the Noflex but I would suggest that once every couple of years you do blow out your vent lines what ever you use.
You do not need to use ice the Noflex will move the stuff around lots once used.
As for scale sometimes people see in there tanks dark clumps on the insides. It is usually build ups of toilet paper not scale If you do the treatment were you fill and let the tank sit for a day the Noflex will remove it.

If you do get scale and it is usually on the Vacuum side of the system you can use acid toilet bowl cleaner It is usually 8 >10 Hydrochloric acid and safer for the user to handle rather than 30> % strength.
Soak parts in a watered down solution (like the duck bills )

In Vancouver there are many marine stores carrying it ; ask the store owner what comments he get from people using the Noflex and look at how many facings of the Noflex on the shelf than all the rest (if there are any others left) .
There is a reason

I haven’t written any books but when I was in the business my charge out time for industrial sewage treatment systems is $1500 a day so I know something about **** .

Northern Spy said:

If the deck pumpout tube goes to the bottom of the tank (which mine does, about 3/8"), how are you supposed to get ten lbs of bigger, homemade, ice cubes in through there?

Click to expand...

Ic3e CUBES might not make it, but I've never heard of any problems using icemaker "discs." If you can't use those, unless the tank has a cleanout port, I guess you prob'ly wouldn't be able to use ice.

Tom.B said:

How can you tell? My ejection is below the waterline and all the hoses are solid, not clear.

Click to expand...

But the dockside pumpout hose SHOULD have a sight glass (about a 1 foot section of clear plastic pipe close to the end) in it.

Which, btw, you should always watch during pumpout to make sure the tank IS being pumped out, that a blocked vent hasn't caused the pumpout to pull a vacuum that prevents it from removing more than a gallon or two. NEVER just turn pumpout over to a dock hand and walk away.

Great advice as always. I have the original FG tank and would like to put a mega flush on her as you suggested.
As Steve mentioned- I have an inspection cover install on my wish list.



1983 Present 42 Sundeck
Twin Lehman 135's

My holding tanks are black, so I can't tell if there is any sludge build up in them or not. I doubt it however as I completely flush the tanks with clear water every time I pump out.

That is one advantage of having to do the pump outs yourself, you can do flush the tanks to your hearts content. If there is another boat waiting for me to finish, then I only give it one quick flush for each tank, it doesn't take long. And when there aren't any boats waiting, each tank gets flushed until the effluent is clear.

Now, that doesn't mean there aren't any buildups in the tanks or hoses however. Just that I do my best to avoid it and I don't know how the tanks were treated for the boats first 5 years of life.

I made my own vent filter. Go on You Tube, they have everything on that sight. PVC pipe, 2 caps, activated charcoal and some fiberglass filter material from the pet store. The charcoal and the fiberglass are for fish tanks. I spent less than $25.00 and it work great.

Be careful making your own filter. Water filters can be packed tightly with charcoal, but not vent line filters. There must be a lot of air space around the charcoal pieces to allow plenty of air flow in and out of the vent line or you create a blockage instead of a filter. So make sure your charcoal pieces are in shapes that won't pack together.

Sea Q said:

If you have the sludge problem --
Pump the tank out as much as possible and for every 20 liters of tank add about one oz of Noflex
Wash it down the toilet with enough water to fill the tank to 90 % full and leave it for 24 to 48 hours . (If you have vacuum flush toilets try not to get the powder on the rubber or ball)
If your tank sludge is more than 50 % of the tanks volume you may have to do this a second time.
Then use the Noflex on a routine basis once every couple of days to keep control of the smells and sludge.
If you do not have the luxury of time use a tablespoon every day (per person on board ) for a month and then cut it back once you see the tank walls cleaning up.

As for scale sometimes people see in there tanks dark clumps on the insides. It is usually build ups of toilet paper not scale If you do the treatment were you fill and let the tank sit for a day the Noflex will remove it.

I haven’t written any books but when I was in the business my charge out time for industrial sewage treatment systems is $1500 a day so I know something about **** .

Click to expand...

Yeah, Dave, maybe "scale" is what we have, then. Looks like dark clumps built up on the insides of the tank walls -- to just about the halfway mark -- even after 2 seasons of almost-daily Noflex treatment (but while the system is in use).

I could only afford 24 hours worth of Noflex treatment with clean rinse water this time. Filled the newly-pumped/rinsed tank up to above the sludge line with fresh water, added about 2 tablespoons of Noflex, 24 hours, didn't seem to do squat.

I'm not thinking it wouldn't have eventually done squat, just couldn't afford more downtime at this particular moment.

BTW, you still need to pursue that whole Commercial Member thing they do here.

-Chris

I put a tap on the tank top with a valve to the deck washdown pump. Occasionally while offshore I turn on the rinse valve and run the macerator. Maybe ten minutes as macerator is not a continuous run motor. Does a pretty good job of cleaning the tank.

In prepping for haul-out next month I found I could not flush the aft head so the glycol anti-freeze could make the 20’ or so trip to the holding tank. I rarely use the aft toilet but my grandsons have used it frequently this year and I suspect have not “pumped” the manual plunger adequately to move the flush water “up the hill” to the vented loop and as a result, I think there’s a “dry” clog somewhere along the 1 ½” pvc sanitary hose. Will a product like NoFlex digester solve what I think is my problem with a hose clog?

Artfull, I don't know if Noflex would clear it or not. The problem I see is that you can't get the Noflex to the clog. I think you're going to have disassemble something and poke the clog with a stick or pressurize the line somehow.

artfultune,
Kids put all kinds of stuff down toilets. They think it's a machine to make things disappear.

well HopCar, wasn't as bad as I thought..pulled the holding tank sanitary hose and got a 25' length of old garden hose..fairly stiff but slimed it with dish soap and pushed til it poked its' head out in to the tank..met some sloppy resistance on the way down but got decent results

Well done Artfull. Clever to use the hose as your poker. I'll remember that trick.

Paper towels

I made a big mistake last weekend leaving a roll of paper towels in a washroom .Two visitors on board wiped down the sink after washing their hands and thru the towels in a vacuum flush toilet.
First time it was what the hell.
Second time was stupid me leaving the roll there

So, where in the system did the towels get to?