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Cpd

Bleaching water system

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I have installed and commissioned my new water system and now need to purify the system by flushing it with Sodium Hyperchorite 5% 

however i cannot find the right stuff locally and struggling on line..... it seems to come in large quantities for swimming pools.... and I only need a few litres.

@JSHarris having done this yourself, can you recommend something that’s easily available and will do the job ? I may be over thinking this. Thanks 

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Pop down to your local pool, ask to see the manager and get a 5 liter tub of it. Cost? Nowt.

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I take it you mean sodium hypochlorite rather than hyperchorite. You can get it from any farm supply place (it is what is used for cleaning milk lines and parlours) if you want it at c.15%. It is another name for common garden bleach when it is at 5-6%, therefore available everywhere. Calcium hypochlorite (it is in solid form, tablets or granules) is what is normally used for swimming pools, also available from janitorial outlets.

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23 minutes ago, Cpd said:

I have installed and commissioned my new water system and now need to purify the system by flushing it with Sodium Hyperchorite 5% 

however i cannot find the right stuff locally and struggling on line..... it seems to come in large quantities for swimming pools.... and I only need a few litres.

@JSHarris having done this yourself, can you recommend something that’s easily available and will do the job ? I may be over thinking this. Thanks 

 

 

Unscented, non-thickened, domestic bleach (the cheapest supermarket own brand) will do the job OK.  Bleach is usually around 6% to 9% hypochlorite concentration, so dilute it a bit to get 5% (check the label on the bottle).  Pool shock (calcium hypochlorite) is another option (cheaper, in terms of the volume of bleach you can make up from a tub) but may not be as easy to get hold of.  I've used both bleach and pool shock and both work fine.  Pool shock is usually around 65% to 70% hypochlorite, so a lot stronger than domestic bleach.

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Thanks All  - non perfumed and non - thickened standard  bleach.  Got it 

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4 minutes ago, AnonymousBosch said:

Eye protection ...✔️

 

And gloves...

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1 hour ago, Cpd said:

I have installed and commissioned my new water system and now need to purify the system by flushing it with Sodium Hyperchorite 5% 

however i cannot find the right stuff locally and struggling on line..... it seems to come in large quantities for swimming pools.... and I only need a few litres.

@JSHarris having done this yourself, can you recommend something that’s easily available and will do the job ? I may be over thinking this. Thanks 

What about Milton steriliser - 5litres for £10.00 - it is basically sodium hypochlorite. Safe too. Used for baby bottles amongst other things.

Edited by Carrerahill

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6 minutes ago, Carrerahill said:

What about Milton steriliser - 5litres for £10.00 - it is basically sodium hypochlorite. Safe too. Used for baby bottles amongst other things.

 

 

Milton is only a 2% bleach (sodium hypochlorite) solution, so weaker than needed to disinfect a water system.  You can make "Milton" by just diluting plain domestic bleach with water and maybe adding some salt to it. 

 

The reason for needing a stronger hypochlorite concentration when disinfecting a water system is really to do with the limited contact time.  Milton works because stuff is kept in contact with it for a fairly long time, but with disinfecting a water system you really just want to flush it through with a strong enough solution to pretty much guarantee killing stuff off in a minute or two.

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Why do you need to use unthickened bleach?

Is it the thickening agent that is the problem, or is the bleach less effective?

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2 minutes ago, SteamyTea said:

Why do you need to use unthickened bleach?

Is it the thickening agent that is the problem, or is the bleach less effective?

 

It's the thickening agent, could be one or more of a fairly wide range of stuff, from sodium chloride through to sodium lauryl ether sulphate, plus probably a bit of sodium hydroxide.

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1 minute ago, JSHarris said:

It's the thickening agent

Does it make the bleach less effective, or just clog things up?

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Just now, SteamyTea said:

 

Does it make the bleach less effective, or just clog things up?

 

It makes bleach more effective when used to clean things like toilets, as it acts as a surfactant (makes the bleach wet the surface more easily) and as a thickening agent to increase the film thickness and contact time of the bleach on a surface.  For disinfecting a drinking water supply the snag is that the thickening agent may result in residue being left behind in the nooks and crannies of the pipe work, really anywhere there is a fairly low surface flow velocity.  You ideally want the disinfecting agent to flush out/decompose quickly, so there's no residual stuff in the system.  Hypochlorite is fine, as it breaks down quickly, but the other stuff doesn't break down very quickly and is designed to "stick" to surfaces.

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This is what we used anytime when working on potable water supplies when contamination was a possibility. Easy to handle and you can make up to whatever CL concentration you want.

 

https://www.ferret-technology.com/product-page/chlorus-tablets

 

 

But, there are much more effective sanitising products out there for the food and beverage industry. Chlorine solutions will kill everything, but they are not so effective and lifting residues and material from pipes. I'd suggest a flush through first with a beer line cleaner or similar. Especially if you think there might be mould, dirt etc in the pipes. 

Edited by Conor

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2 minutes ago, Conor said:

This is what we used anytime when working on potable water supplies when contamination was a possibility. Easy to handle and you can make up to whatever CL concentration you want.

 

https://www.ferret-technology.com/product-page/chlorus-tablets

 

They are hypochlorite tablets, a bit easy to handle than the granular hypochlorite mentioned earlier.  They have the advantage of not being so likely to decompose due to atmospheric moisture getting to them, but the disadvantage of being slower to dissolve into solution.  I have some that I used when our borehole was sitting idle, during the prolonged saga around getting it to work properly.  I used to drop one of those down the borehole every now and again to keep it bacteria-free whilst we were messing around trying to get all the fine sand out of it.

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1 hour ago, Conor said:

This is what we used anytime when working on potable water supplies when contamination was a possibility. Easy to handle and you can make up to whatever CL concentration you want.

 

https://www.ferret-technology.com/product-page/chlorus-tablets

 

 

But, there are much more effective sanitising products out there for the food and beverage industry. Chlorine solutions will kill everything, but they are not so effective and lifting residues and material from pipes. I'd suggest a flush through first with a beer line cleaner or similar. Especially if you think there might be mould, dirt etc in the pipes. 

 

My experiences exactly, one of the instruments I look after is a faecal occult blood analyser. The wash solution is just a dilute bleach and it's damn-all use for getting fatty residues out of the measuring cuvettes. Q-tip and fairy liquid time...

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But you should NEVER consider disinfecting a private water supply with anything that contains surfactants, as it will take days of pumping to clear the residue.  People have done it by accident, and described just how long it's taken to pump out the mess, on the US well forum where I received a lot of very useful advice, and there are now always warnings to only ever use plain hypochlorite.

 

There's a world of difference between cleaning out lab equipment or beer lines and just disinfecting a private water supply as a part of the commissioning process.

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