Chlorine Tablet Sitting in Seawater Supply Line

[seafox]

I've tried drinking bleach and vinegar....made me feel a little sick and I still smell nasty. I better go and see Dr Putnam again.....

[coot]

Originally Posted by rebel heart

He's probably going to switch to fresh water while docked, as you did. We've heard that really fixes a lot of the problems lickity split. That being said, I don't want to spend $300 on pumps and plumbing to "fix" a problem that will show back up in full force the minute we pull away from the dock.

On my boat, the shower head is on a long hose that easily reaches to the toilet. To flush with fresh water, I hold the shower head over the bowl and turn on the shower briefly. The cost to flush with fresh water is zero, and I have no connections between my fresh water system and the sewage hoses.

In the summer, I usually use this method whether at the dock or not. It is just part of my water budget.

Originally Posted by Tom Spohn

For the stink in the bowl from dead marine life in the salt water just squirt in some "CP" made by Raritan Engineering. It will clean the bowl and the enzymes will take care of the bacterial smell.

I've used the CP this way, but found that you can do the same thing for less money with the green holding tank treatment from Sealand. It's available at West Marine in the US. Make sure to get the GREEN stuff and not the blue, which comes in an identical bottle with a nearly identical label.

Instead of flushing a whole tank-treatment of the fluid, I decant it into a small bottle and squirt a small amount into the toilet after I finish flushing. All it takes is enough to give the water that remains a slight green tint.

I find that it can sometimes be helpful even if you flush with fresh water.

[Cruisingdad]

I hesitate even posting this, as it is completely contradictory to everything that has been said above. I welcome a chemical engineer to rebute this. I am just a chemist, but have not worked in this area. If there is a plastics/synthetics engineer on this board, please tell me where I am wrong. I learn something new everyday.

You say bleach is the worst thing you can do for your tubes, I assume you mean cholorine? Have you verified that with your tube mfg? Mine said it would have no effect on the tubes at that molar concentration. I contacted my tank mfg and he laughed at me (yes laughed), then said it would have absolutely no effect as they also mfg their tanks for shipment of high molar concentration chrlorine all over the world. A CL tab drop in tank tab is a joke to them.

I find it difficult to believe that the rubber seals will not have a problem over time with the chlorine. It take a toll on the tank on a household toilet. However, to date (1 year+ running) I have seen no effect. Thus, at the risk of being chastised by everyone here, let me give you first hand knowledge:

I have always had a problem with the stinch in the head. I imagine everyone that salt water flushes (and even fresh-lake water) has. There are products that help, but short of a freshwater connection, there is going to be little you can do to get over it. WELCOME TO OWNING A BOAT!!

I met a gentlemen (an engineer) who told me what he does. He put in a large strainer (bronze) Amazon.com: Perko - Arg Series Raw Water Strainer 1-1/4'': Sports & Outdoors and drops half a teflon tab and half a chlrorine tab in the strainer. He has absolutely NO stink in his head at all. Period. He told me to do it too.

I refused until I knew more. I contacted the hose, tank, and head mfg and discussed the rediculous notion. They saw no problem at those concentrations. The head mfg said I should not use bleach (I am not sure why there is a difference unless it is because the molar concentration of CL in bleach is considerably higher when poured directly into the head, which I guess would make sense, I have not researched that), but said they saw no issues.

I still wanted more proof. He showed me another boat that has been using that system for 10+ years (as I recall now). Both of the boats are taswells. Mine is a Catalina.

I pulled the rings off the strainers last weekend, expecting to need to replace them, and they are fine. That has the strongest CL concentration, the rest is dilluted, obviously.

I only made one change: I did not use the bronze strainers, I used the "Plastic" onces. I have absolutely no problems there, except I have noticed it breaks down the SS strainer quickly. I will try a plastic one next, as the plastic has held up well.

I can understand why everyone on this board has told you no. They had the same concerns as me. I cannot give you a 10+ year first hand experience... but do your own homework and call your hose mfg and tank mfg. I got different answers than what has been said above.

- CD

PS I have ABSOLUTELY no smell in any of my heads. Unbelievable. I also feel you will go through rebulds on your head more often as the rubber breaks down. I am not reccomending you do this, nor would I reccomend it to anyone in Mainsheet. I am basically running this test on myself as I have the funds to fix it if it screws up. I am my own test subject. However, I can say it works (very well) and have seen boats that have used this system many years later that have shown NO negative effects. I respect Hello's and other opinion on this board... just dissagree as that has not been my findings.

Ok... you are all free to give me a rationing of it!

[hellosailor]

CD-
I would suggest that some plastics won't be affected by some concentrations of chlorine, while others will.

Who among us really wants to research the specific manufacturer of every plastic or rubber part on the head plumbing, in order to find out if we've got the safe stuff?<G>

Obviously some plastic is safe with some bleach for some time, since it is sold in plastic bottles. Which only sometimes get brittle and leak. But if you put bleach in a common sprayer bottle (i.e. windex sprayer, or tub and tile cleaner sprayer) you'll find that some of them go belly up only days after getting the bleach in them, while the 'identical' bottles sold as mildew killer with bleach in them keep on working.

Much safer to keep the corrosives out of the system, unless you know that particular system is safe for them. You'll find a 24 carat solid gold (chemical resistant) plate with the approval stamp, bolted to the lower rear side of the head, under the hinges, if yours is really rated for resistance to corrosives.

Honest.<G>

Better yet, ask a plumber how they love replacing toilet parts in homes after the "tank dunks" have made seals and floats rot out. But housewives love to keep putting 'em in the tank, and supermarkets sell 'em every day.

No thanks.

[Cruisingdad]

Hello,

As I said, I always respect your opinion... though we may not always agree (you just don't realize I am ALWAYS right... smile).

Yes, I agree on the plastics. Different plastics, different applications. However, the only plastics on a plumbing system that should be of concern are those that are difficult to change (ie, your black water hose... a nightmare I would just pay a yard to do) or those that would quickly degraded. Again, I am my own test subject here, so am not advocating to anyone. However:

I will take a clean smelling head where I have to replace my seals every couple of 2-3 years on my head (easily accessible and easy to do) versus smelling that rotten egg, decaying skunk stinch that fumagates the whole boat everytime I flush. I am telling you: MY BOAT SMELLS BETTER THAN ANY BOAT I HAVE BEEN ON, PERIOD (Excepting the 2 Taswells that use this system too). We do not realize it, but that smell gets into everything and is not isolated to the head. As a weekender, who cares. As a liveaboard, much more of an issue. I did notice as a LA, the smell was a lot less because there was less decay (due to constant use). However, these blue tabs also keep the tank fairly clean. I see it having no effect on the Ca depostis. Introducing a low concentration muratic acid could fix that. Also, without getting into the grosser side of this conversation, the chlorine has done a fair job of breaking down the contaminants in the tank.

How does a LectraSan work? It is post tubes, I realize that, but isn't it basically supercharging the plates with current that forces the chloring to seperate from (well, soidum or potassium in this instance... not always) which super-chlorinates the water and waste in a high molar concentration Cl solution? It breaks down the waste and reduces (almost eliminates) bio load (ie, bacteria and virus). Wouldn't hours/days in a low concentration Cl have the same effect as minutes in a high Cl?

This could turn into an intersting subject....

[rebel heart]

CD -

I'm with you. Chlorine is in nearly every municipal water supply in the developed world these days, and it's flowing through clay, plastic, metal, glass, and gosh knows what else. If some cheap piece of crap lawn sprinkeler can handle the chlorine, I would expect something that is costing me up the butt for "marine grade" would work the same.

Not only that, but if you're using fresh water in your marine toilet, and that fresh water is from a garden hose, chances are very high that you're using chlorinated water anyway.

The strainer thing with the chlorine tablet that you're mentioning is the same thing my friend and I were considering doing. We're going to try to add some type of water softener as well, although we might wait on that one.

We'll let you know how the results go!

[Alan Wheeler]

Cruising Dad, you are mostly right. Infact, most all plastics are actually made with Chlorine. Most all "common" plastics are chlorine safe. So hoses should not be harmed by Chlorine at all.
The Lectrasans use an electrical current to produce Chlorine from Sodium Choride. Two other by products are produced. Hydrogen and Sodium Hydroxide.
In a strong enough concentration, Chlorine will bleach. As I said above, it woudl bleach the scum in the toilet bowl, but the new smell of chlorine would be just as bad as the old smell of the toilet bowl scum.

[cooper]

My solution is a porta potty !! Laugh away, but it meets all holding tank requirements. Is easy to thoroughly clean. Is cheap to buy. Requires no through hulls, extra pumps, or a spagetti of hoses. Can be used up on deck with a good book for the ulitmate in morning constitutionals (Secluded anchorage only please) It wont work on a high "turn over" boat, but even then you can buy spare holding tanks for them very cheaply. Compare doing a complete pull down and clean of the built in type with a porta potty. Outside shore limits, you tie a rope onto the handle and throw it overboard. One hour later cross eyed fishies, and sparkling throne............you know it makes sense !!

[Pblais]

The issue of Chlorine I brought up earlier was meant more from the Chemical nature of how a tank works. There seems to be an idea here that adding Chlorine will somehow reduce the smell and that if more were added it would reduce it more. I would contend beer would work far better even if you drank it first.

Chlorine will indeed kill biologic activity but with a properly vented tank it's a better thing to keep them alive, healthy, and eating waste. The really foul smells from a head come from anaerobic oxidation (decaying dead biology in the absense of oxygen) while aerobic oxidation actually breaks down the waste with little smell at all. It's what goes on inside a septic tank in someones back yard (mines in the front). Introduction of the septic tank treament products might be a good idea since they promote oxidation.

Anaerobic oxidation produces the worst smells and it can also can come from an unvented (clogged vent) tank since the healthy creatures need air to live. Killing everything in your tank just leaves the rotting dead bodies that increase the smell rather than allowing some of it to be eaten and converted to CO2. It's why composting heads produce so little smell. You can do anything you like if you empty the tank frequently since in a short period of time fewer things rot. If you have to haul your waste around it's better to let the aerobic oxidation have at the waste.

I use a Purasan head. It mixes Chlorine (Calcium Hypochlorite it's an oxidization) into the soup and energizes the waste for 2 minutes thus killing biologic activity before discharge through an intense oxidation process. Killing the activity before discharge is what MSD type II and Type III treatment systems do and actually what most municipal treatment systems do as well using larger scale processes. Adding Chlorine in this case is required because it uses fresh water unlike the Electra San that uses salt water to add the Chlorine chemical component. Since nothing remains aboard it's the only safe approach possible. MSD Type II heads have nothing in common with a holding tank since they indeed kill all biology but they do use chemical oxidation instead of aerobic oxidation because it's faster.

[Cruisingdad]

I appreciate all the replys. I respect everyone's opinion here as they typically mirror mine on most things. I knew this would get many responses, beause like you, I have been VERY skeptical.

There are many people here that have boated and cruised longer than me, many who have not. But it does not take Tom Neale to tell you that there is NOTHING aneronbically that totally removes the waste smell. I have tried everything, including KO - a product we used for years, which has many limitations (inlcuding the only cleaning substance being CP... all of these expensive and cumbersom for long trips). Even with these products, there is a smell in the head when you flush - for reasons already discussed. That is what "irritates" most boaters.

Trust me for a moment, when I tell you that if you put in the teflon (to coat the rings) and Cl tabs, you will have NO smell. Let me say that again, NO SMELL. Nothing. Notta. Not a single thing. Your boat will take on a new comfort!! (smile).

For those of you using chemical treatements, you can try this just once (just in case there are some hidden problems we have not discovered yet). You will be hooked immediately. For those of you with an aerobic system - it will screw it up for a long, long time so you should give serious thought to it before impementing (as the residual Cl will be in the tank for a long time, screwing up your bacteria). For those of you with an Al holding tank... I would not suggest it. The Cl will likely increase the oxidation of the metal (pitt it). Not a good thing over time.

For those with a aerobic system, there is a product out that introduces oxygen into the tank (basically a fish tank aerator) that, with the oxygen, should allow the aerobic bacteria (not stinky) to overpopulate the anerboic (stinky). I know Catalina has made mention of putting that system into their manufacturing (whether by option or standard, I do not know). You can try that. I have heard mixed results. However, that will just be tank based and will have no effect on the rotten egg smell in your head (for reasons explained earlier).

I advocate nothing to anyone here. I don't want someone writing an article to Mainsheet telling them how CD said they should be dropping Cl & teflon tabs into their H2O supply line. Do it at your own risk, or stay in touch with me and I will let you know the long term effects of the tablets. For me personally, it is the only thing I have found that is inexpensive, portable, and actually works. Is it a long-term solution.... only time will tell.

- CD

[rebel heart]

I keep falling back to the ideas that:

- Fresh water from a municipal source has chlorine. I haven't heard anyone saying that tap water (which contains) chlorine is bad for pipes or anything else. In fact, fresh water (which again, has chlorine), is recommended as a better approach to flushing the head. Obviously not because of the chlorine, but it can't be doing much wrong.

- Even if it does trash all my fittings every few years, which I haven't found any empirical evidence that it will, if I have to pick up new stuff every few years and in the meantime it smells like roses in there, I'm sold.

[Cruisingdad]

Rebel,

It is true that Cl is used in municipal water systems. I cannot speak for every country, but I THINK the limits in the US are about 4mg/L, which I believe is set down by the EPA. Now I will tell you right now that I have had drinking water much stronger than that (Bubba fell asleep when pouring it in)... but the point is, it is in a vastly lower concentration than what is introduced by a Cl tab. On a positive not, the Cl is primarily concentrated in the strainer, so adverse effects should (SHOULD) show up there first. My O-ring showed no negative effects, but this system has not been in place for very long. Out of prudence, I would find out who makes my waste hose and holding tank and verify that Cl at that concentraion will have no effect on their product. Replacing a black water hose would be an absolute nightmare on my boat... I assume yours too.

Keep an eye on your head if you put this in. Rubber will generally swell as it starts to go bad (and may start turning a bit white). Squeeze your supply line hose or pull it off to see if it is starting to feel brittle. Most supply line hoses are not that difficult to replace, but would not be any fun either. If you use a SS basket, you may realize it starts deteriorating. I would try a platic one instead. I have no idea how well that will hold up, though.

Let me know how it works. As they say before the loud beeps: THIS IS A TEST... IT IS ONLY A TEST... (smile)

- CD

[southernman]

I'm a water treatment engineer - I dose town water supplies every day. Corrosion rates are very low if you keep the chlorine dose rate below 0.5 ppm. They can be measured in the very low MPY range. We measure these with on line corators every day. By putting one chlorine tablet in the head, it won't ever get high enough chlorine reserves to do any damage. There is a fairly high biological loading in a head so the FAC or free available chlorine reserve won't be high enough to corode anything.

I have used Spirit of Salts (the retail name) of Hydrochloric Acid in our Lavac for years and never had any scum or smell. A cap full every week, leave it for an hour, scrub and flush - very simple. Of course I give it a clean with a bathroom type spray as well for hygene. Try it - it's cheap and you don't need all those fancy branded chemicals. Waste of money in my books.

Cheers

[hellosailor]

Southernman-
I don't doubt what you say, I jsut can't help wonder.
"Corrosion rates are very low if you keep the chlorine dose rate below 0.5 ppm. "
How do you establish that dosage? Is there a standard size chlorine tablet for heads? And way to ensure proper dilution and application to ensure that dosage really happens?

I'm only familiar with pool chlorine tablets, no idea what's available for heads. I'm tempted to try lowering a pinholed PVC pipe full of them overboard at the mooring to keep critters away from the prop.<G>

[GordMay]

Originally Posted by southernman

... Corrosion rates are very low if you keep the chlorine dose rate below 0.5 ppm ...
By putting one chlorine tablet in the head, it won't ever get high enough chlorine reserves to do any damage. There is a fairly high biological loading in a head so the FAC or free available chlorine reserve won't be high enough to corrode anything ...

Thanks for your expert comments southernman.

Q1. Will low dosages of Chlorine, under 5 ppm, be effective in sanitizing sewage?
Q2. Don’t the low residuals (free Chlorine reserve) indicate incomplete sanitizing?

As I understand it, essentially clean potable water can be kept that way with a low dosage of Chlorine.
“Residual” Chlorine is that Chlorine remaining after cleansing. A higher residual indicates that the cleansing has been accomplished, and some free Chlorine remains. A lower residual indicates that cleansing may be incomplete.

Standard water main (not sewage) shock-chlorination procedure after full-flow flushing: (what I use in my construction inspection work)
1. A dosage of 50 to 200 mg/L (ppm) of free chlorine is evenly distributed through out the piping
2. Undisturbed contact time with the piping for 24 hours
3. Retesting of the chlorine residual after 24 hours (> 10 mg/L (ppm)
If the chlorine residual is less than 10 mg/L (ppm) after 24 hours, repeat the entire procedure above.
If the beginning dose is 50 to 100 mg/L (ppm) and the remaining residual after 24 hours is less than 10 mg/L (ppm), this indicates severe bio-fouling or large amounts of dirt, slime , or other contamination are present.