Cryptosporidium how to clean water tanks?

[VicS]

What are you trying to kill? What concentration are you planning to add? The problem with the bleach wasn’t so much the fact some would end up in the sea - it was the amount. The quoted concentration was 5% - that’s the sort of concentration in typical thin household bleach. So basically fill your tanks with hundreds of litres of bleach and no plan for disposal. All for a parasite that can be physically flushed out!

Now if you were looking to treat mould/bacteria that is clinging to tank walls, pipework etc then it’s much more susceptible to chlorine and doesn’t need 5%. Personally I’d use Milton (or a cheaper equivalent) that is intended for sterilising baby bottles as it’s doesn’t seem to have the taste/smell of traditional bleach. I suspect if you asked your marina they would not approve of you dumping 200L of dilute Milton in their water either. Given you’ll want a bit of contact time and probably some agitation - fill tanks go for sail, drain tanks slowly, return to port and fill with fresh water and it’s not going to kill any fish.

You could ask the manufacturer how dilute Endosan should be before discharge to drain.

The recommended dose for sterilising a tank with Milton fluid is 30ml per 5 litres. Allow to soak for 15 minutes and then rinse out.

For sterilising drinking water use 2.5ml per 5 litres. The water is usable after 30 minutes.
.

 

[thinwater]

AIUI bleach/hypochlorites are highly toxic to aquatic life and I read the abstract & summary and nothing jumped out of this that said otherwise. If you're able to translate into O level chemistry if they actually found it's now OK to discharge I'd be interested to hear as I would like to hit our (non crypytosporidium) tank with a shock dose of something that I can easily dispose of. Thanks.

It's quite simple to neutralize bleach. Google it. Hydrogen peroxide is one of the most common methods.

Every sewage treatment plant chlorinates the effluent after treatment, and then dechlorinates before discharge.

 

[chrishscorp]

It's quite simple to neutralize bleach. Google it. Hydrogen peroxide is one of the most common methods.

Every sewage treatment plant chlorinates the effluent after treatment, and then dechlorinates before discharge.

Your in America, our sewage treatment plants look out the office window and if there is a black cloud in the sky dump as much untreated sh1te as they can in our rivers, chalk streams and bathing waters as is possible.

 

[Mister E]

The recommended dose for sterilising a tank with Milton fluid is 30ml per 5 litres. Allow to soak for 15 minutes and then rinse out.

For sterilising drinking water use 2.5ml per 5 litres. The water is usable after 30 minutes.
.

Can this be pumped directly overboard or does it need something adding to neutralise it?

 

[C08]

I use a mixture of hydrogen peroxide and silver as a bug killer in spray systems, and in my potable water tanks. It's made by Endosan (endosan.com) whom I have recommended on the forum previously.

I requested advice on Cryptosporidium from them as a source of info for anyone with a boat in the affected area.

Here it is.

EndoSan8 is indeed effective at eliminating Cryptosporidium, and I have included our comprehensive protocols for your reference.

To address your specific requirements, please adhere to the following guidelines:

1. Shock Treatment at 500 PPM: Administer a shock dose of EndoSan8 at 500 parts per million (PPM) for a duration of 1 hour. This level of treatment is typically sufficient to resolve contamination issues. However, for enhanced efficacy, extending the contact time to 4 hours is advisable. This prolonged exposure can potentially yield superior results due to increased contact time with the contaminants.
2. Enhanced Disinfection for Suspected Biofilm: If there is a suspicion of biofilm presence within the system, a more rigorous approach is necessary. Administer a shock dose of EndoSan8 at 2000 PPM and maintain this concentration for 8 hours. This high-level treatment ensures comprehensive disinfection by penetrating and breaking down the resilient biofilm matrix.
3. Personal Protective Equipment (PPE) and Test Strips: Refer to the attached protocol document for detailed instructions on the appropriate PPE to be utilised during the disinfection process. The selection of test strips is crucial for accurate monitoring. You can conveniently purchase the necessary test strips from our online store at EndoSan Test Strips Online Store. The available options include:
   
   • 0-100 PPM Test Strips: Utilised for continuous dosing scenarios.
   • 0-1000 PPM Test Strips: Suitable for verifying a 500 PPM shock dose.
   • 0-5000 PPM Test Strips: Essential for monitoring high-level disinfection treatments aimed at biofilm removal.
4. Ongoing Control with EndoSan8: If you choose to maintain ongoing disinfection, EndoSan8 can be utilised to control your system between 10-35 PPM. This concentration range is suitable for drinking water and is commonly employed by cruise ships to keep their systems disinfected until their next fill.

To determine the exact amount of EndoSan8 required for your specific system, including pipe volume, cold and hot water storage tanks, please use our online dosage calculator at EndoSan Dosage Calculator. This tool provides accurate dosage recommendations tailored to your system's specifications.

Adhering to these protocols will ensure the effective disinfection of your boat’s water system, providing safe and clean water. Should you require further assistance or clarification, please do not hesitate to contact us.


I have no connection with Endosan except as a very satisfied, commercially qualified, user for agricultural spraying, and privately for the boat for many years . This is posted as it provides one answer to the OP's question about Cryptosporidium.

Thanks Sara.. for the info and getting expert advice on the Crypto parasite.

 

[Fr J Hackett]

Sorry I should have said “nobody on here”

I wouldn't bet on it there are a couple of absolute Lou Lous in the lounge today, I will leave you to search them out.

 

[st599]

The recommended dose for sterilising a tank with Milton fluid is 30ml per 5 litres. Allow to soak for 15 minutes and then rinse out.

For sterilising drinking water use 2.5ml per 5 litres. The water is usable after 30 minutes.
.

But Milton is a 2% solution of Sodium Hypochlorite and Cryptosporidium is resistant to chlorination until a 5%+ solution.

 

[oldmanofthehills]

But Milton is a 2% solution of Sodium Hypochlorite and Cryptosporidium is resistant to chlorination until a 5%+ solution.

Hence hydrogen peroxide - such as used to make blond hair. Not very stable so if diluted with enough see water probably not that much of an issue

If that is there is any real problem to be solved

 

[VicS]

Can this be pumped directly overboard or does it need something adding to neutralise it?

It probably shouldn't be although it is a pretty dilute solution and if discharged slowly into moving water the concentration is going to be very small.

The quantity of Milton sterilising fluid, used at the suggested rate, for sterilising a 200litre tank could be treated with 40ml 30%/100vol hydrogen peroxide

Remember though the suggested treatment is for a routine sterilisation of a tank, not for treating cryptosporidium.
.

 

[thinwater]

But Milton is a 2% solution of Sodium Hypochlorite and Cryptosporidium is resistant to chlorination until a 5%+ solution.

Also oldmanofthehills: Do you have a link to a government or other respected source recommending these concentrations (50,000 ppm)?

Normally it is dose and time, and I'm having a very hard time believing that much less will not work, given reaction/soak time. The numbers I am seeing from NIH suggest 120-1000 ppm-min, or for example, 2-17 ppm for 60 minutes.

Or this, from CDC:



Show me a link, or I'm calling the high concentration requirements fiction. I showed you mine.

Cysts are resistant to standard drinking water doses of 0.5-1 ppm for a few minutes, but not higher doses for a few hours or overnight.

Just Google it.I'm sure there is UK research posted by the government.

 

[Beneteau381]

Ok enough can we stick to the problem of cleaning water tanks.

Dose the tank with household bleach as I detailed earlier on. I also posted the link from Chlorox confirming that it decomposes quickly in to sea water components

 

[ylop]

Also oldmanofthehills: Do you have a link to a government or other respected source recommending these concentrations (50,000 ppm)?

Normally it is dose and time, and I'm having a very hard time believing that much less will not work, given reaction/soak time. The numbers I am seeing from NIH suggest 120-1000 ppm-min, or for example, 2-17 ppm for 60 minutes.

Or this, from CDC:

View attachment 177326

Show me a link, or I'm calling the high concentration requirements fiction. I showed you mine.

Cysts are resistant to standard drinking water doses of 0.5-1 ppm for a few minutes, but not higher doses for a few hours or overnight.

Just Google it.I'm sure there is UK research posted by the government.

U.K. Drinking Water Inspectorate seems to say it’s highly variable depending on how you do the experiment or where the crypto originated from: https://cdn.dwi.gov.uk/wp-content/uploads/2020/10/27110709/dwi0805.pdf

One of the studies they quote says 8000-16000 ppm for 24 hrs!

 

[VicS]

Dose the tank with household bleach as I detailed earlier on. I also posted the link from Chlorox confirming that it decomposes quickly in to sea water components

But the paper by Lister to which you also linked says, "It is apparent from these results that the main reaction in the decomposition of sodium hypochlorite is the one to chlorate, and only a small part goes to oxygen." Referring to the reactions

2NaOCl → NaClO₂ + NaCl​

and​

NaOCl + NaCIO₂ → NaClO₃ + NaCl .​

.

 

[ghostlymoron2]

How do you know your tank contains cryptosperidiam? Or did I miss this bit? If you haven't refilled since the problem arose, just sail round to Salcombe to fill up again.

 

[oldbloke]

Much better class of disease in Salcombe. None of your common muck