Cleaning Fresh Water Tank

[Hydrozoan]

Only for a few months at most ..... but the article is claptrap anyway.

Richard
BSc (Hons) DIS (Polymer Chemistry)

Just so long as you keep them in the fridge! http://www.ncbi.nlm.nih.gov/pubmed/17707454

Mrs H is no Yorkshireman, but she also fills a bottle with water as do you. Perhaps her and your C19th ancestors used the everlasting antimony pill https://en.wikipedia.org/wiki/Antimony_pill.

On topic, we have used Puriclean (at recommended dosage once a year, on refilling at the start of the season) and the same maker’s tablets (at the recommended dosage), in a stainless steel tank for about 10 years without any apparent leakage.

 

[navrep]

I used Tesco bleach in my tank - flushed it through twice - water was fine after that - I have to admit I wasn't very scientific over the quantities - not very much bleach and flushed it through 'til I could no longer smell it.

 

[RichardS]

Just so long as you keep them in the fridge! http://www.ncbi.nlm.nih.gov/pubmed/17707454

Mrs H is no Yorkshireman, but she also fills a bottle with water as do you. Perhaps her and your C19th ancestors used the everlasting antimony pill https://en.wikipedia.org/wiki/Antimony_pill.

But if I invited you onto my boat for a refreshing glass of water (although that's a bit too "Yorkshire" even for me!) and gave you the choice of water from my well-used self-filled bottles (where the antimony has been well-leached out) or a nice new shop-bought bottle (where the antimony is still nice and concentrated) ....... which would you choose?

Richard

 

[sarabande]

If you look at the chemical constituent of it its not the same as bleach. Very impressed.

hmm! Have you looked at the MSDS for Puriclean ?
http://www.partinfo.co.uk/files/004A 100g Puriclean MSDS.pdf

Bleach with a few extras.

 

[makingplansfor]

I would not use any chlorine based product, i.e. bleach or even Milton, in a stainless steel tank. Both my stainless tanks developed leaks that had to be welded, and the most likely reason was corrosion caused by the use of chlorine bleach. .

Is there an understood reaction between Chlorine and Stainless Steel ?

 

[Hydrozoan]

But if I invited you onto my boat for a refreshing glass of water ... which would you choose? Richard

Whichever was in the fridge - hoping that seeing the cold beers therein ...

 

[Fantasie 19]

Is there an understood reaction between Chlorine and Stainless Steel ?

Turned my SS flask black when I tried to clean the insides by leaving a bleach water solution to soak... :nonchalance:

 

[vyv_cox]

Is there an understood reaction between Chlorine and Stainless Steel ?

All 300 series stainless steels have problems with chloride attack. We are all familiar with it in seawater but strong chloride containing solutions would make the situation worse. I know of a situation in which a clever plant manager replaced a mild steel bath holding soldering flux, probably killed spirits (zinc chloride) with stainless steel. It corroded almost completely away overnight.

 

[Hydrozoan]

Regarding chlorine and stainless steel, the Nickel Institute says the following:

“Bacterial control and management is often achieved by chlorine dosing. Type 316L(1.4404) stainless steel performs well and the molybdenum additions in this alloy provide greater pitting and crevice corrosion resistance than its Type 304L(1.4307) counterpart. Data to evaluate acceptable free chlorine levels is limited but that available for raw waters suggest up to 2ppm for type 304L(1.4307) and 5ppm for type 316L(1.4404). However, stainless steel can tolerate considerably higher levels of chlorine for short periods of time, as would be the case during disinfection treatments e.g. AWWA Standards C651/652 where 25-50 ppm chlorine are held for 24-48 hours. It is important however that such levels are well flushed through the system immediately after treatment.”

(https://www.nickelinstitute.org/en/...ialsSelectionAndUse/Water/AlloySelection.aspx)

 

[VicS]

Only for a few months at most ..... but the article is claptrap anyway.

Richard
BSc (Hons) DIS (Polymer Chemistry)

What are your grounds for dismissing the article as claptrap. I thought the item to which it refers was purely a factual report on the concentrations of antimony leaching into water stored in PET bottles.

You have some reasons for doubting the validity of the results published ?

But if I invited you onto my boat for a refreshing glass of water (although that's a bit too "Yorkshire" even for me!) and gave you the choice of water from my well-used self-filled bottles (where the antimony has been well-leached out) or a nice new shop-bought bottle (where the antimony is still nice and concentrated) ....... which would you choose?

Richard

You presumably have some further info on the long term leaching of antimony and an indication of how much use is required before little or no more antimony leaches from the PET. Care to share a link or two?

 

[prv]

However, the biggest improvement I made to the taste of tank water was when I changed the 25 year old hoses

Hah, yes, on both boats I replaced the freshwater hoses soon after purchase as a matter of course, using opaque food-grade hose rather than the random transparent PVC tubing on Kindred Spirit (I think Ariam's original hoses were better stuff, but still worth replacing with new). I also replaced Kindred Spirit's flexible bag liner as it had visible growth in it; Ariam's rigid plastic tank has been fine with just a good clean.

Pete

 

[ex-Gladys]

The biggest improvement in water taste on Gladys was to install a General Ecology filter... No involvement with the company other than as a contented customer

 

[Fantasie 19]

What are your grounds for dismissing the article as claptrap. I thought the item to which it refers was purely a factual report on the concentrations of antimony leaching into water stored in PET bottles.

You have some reasons for doubting the validity of the results published ?

Well to be fair... and I have no axe to grind either way... the opposite view could be ... "You have some reasons for believing the validity of the results published?"

I'm not a chemist, but I find that there's usually a learned article along every week telling me that a whole host of things are good for me one week, bad for me the next, repeat ad nauseum, usually by people who do have an axe to grind, or some point to make...

 

[Norman_E]

None of the posts about keeping water in plastic bottles, replacing hoses, or even about which cleaning fluids to use really address the issue that any tank used for holding potable water should have an inspection cover big enough to enable the interior of the tank to be inspected and cleaned. My recommendation remains, the OP should have his tank modified so that it can be done.

 

[vyv_cox]

Regarding chlorine and stainless steel, the Nickel Institute says the following:

“Bacterial control and management is often achieved by chlorine dosing. Type 316L(1.4404) stainless steel performs well and the molybdenum additions in this alloy provide greater pitting and crevice corrosion resistance than its Type 304L(1.4307) counterpart. Data to evaluate acceptable free chlorine levels is limited but that available for raw waters suggest up to 2ppm for type 304L(1.4307) and 5ppm for type 316L(1.4404). However, stainless steel can tolerate considerably higher levels of chlorine for short periods of time, as would be the case during disinfection treatments e.g. AWWA Standards C651/652 where 25-50 ppm chlorine are held for 24-48 hours. It is important however that such levels are well flushed through the system immediately after treatment.”

(https://www.nickelinstitute.org/en/...ialsSelectionAndUse/Water/AlloySelection.aspx)

Chlorine dosing sounds like serious treatment. In a different league from a bottle of Milton, I suspect.

 

[RichardS]

What are your grounds for dismissing the article as claptrap. I thought the item to which it refers was purely a factual report on the concentrations of antimony leaching into water stored in PET bottles.

You have some reasons for doubting the validity of the results published ?

Sorry Vic, I thought your post was tongue-in-cheek to get at me for being a thrifty Yorkshireman!

That "antimony in PET" story hit the headlines about 10 years ago with a huge kerfuffle but there have been dozens of tests over the years since and the results of the original report have been discredited. No study has ever found anything other than trace amounts of antimony - way below any level anywhere near a cause for health concerns.


You presumably have some further info on the long term leaching of antimony and an indication of how much use is required before little or no more antimony leaches from the PET. Care to share a link or two?

Now, that was me being tongue-in-cheek as there is no antimony danger from PET anyway ....... but, if there were, my using and refilling technique would, hypothetically, be presumably be more healthy than always using "fresh" bottles where the contents might have been sitting in a freshly made PET bottle for some weeks with a nice high level of antimony leaching into the water.

 

[vyv_cox]

None of the posts about keeping water in plastic bottles, replacing hoses, or even about which cleaning fluids to use really address the issue that any tank used for holding potable water should have an inspection cover big enough to enable the interior of the tank to be inspected and cleaned. My recommendation remains, the OP should have his tank modified so that it can be done.

Absolutely agree. I added a second inspection cover as the only one was right at the end of a 6 ft long tank. It's a big piece of polycarbonate through which I can see any accumulations of green stuff.

 

[Hydrozoan]

Chlorine dosing sounds like serious treatment. In a different league from a bottle of Milton, I suspect.

I haven't worked out what free chlorine levels would arise from tablets, Milton etc. at recommended doses, but looking at the concentrations in the text I quoted, 2-5ppm doesn't seem a lot and I suspect 25-50ppm or more might arise with a stiff cleaning dose of bleach - but stand to be corrected.

[Edit: for water supplies, WHO says 'Chlorine is present in most disinfected drinking-water at concentrations of 0.2–1 mg/litre' so I presume most chlorine-based disinfection will aim to produce about 1ppm, at least initially. And that's for routine disinfection - 'shock' cleaning levels, as my quoted text exemplifies, will be substantially higher.]

I was (and remain) rather puzzled in the context of drinking water disinfection by your reference to strong chloride solution attack on stainless steel but wonder - especially after your response - if I was (or am) missing something?

I agree about the wisdom of an inspection hatch (and have one myself) and about ensuring pipework is clean.

 

[chrishscorp]

When i purchased my centaur, the infill hose had been disconected 6 years. installed a new hose on the infill, stripped out and put in a new outflow hose and treated the tank to an overnight soak with milton, 4 months on and after several flushes there is still a faint milton taste but it is more than drinkable. I will probably this spring on next refill add a little sodium metabisuphate brewers soloution.

 

[VicS]

When i purchased my centaur, the infill hose had been disconected 6 years. installed a new hose on the infill, stripped out and put in a new outflow hose and treated the tank to an overnight soak with milton, 4 months on and after several flushes there is still a faint milton taste but it is more than drinkable. I will probably this spring on next refill add a little sodium metabisuphate brewers soloution.

However much Milton did you use ? They recommend 30ml/ 5 litres then drain and rinse after 15 minutes.


The winemaker's / brewers sterilising agent is sodium metabisulfite !