Bleaching water system

[Cpd]

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 

[ToughButterCup]

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

[mafaldina]

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.

[Jeremy Harris]

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.

[Cpd]

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

[ToughButterCup]

Eye protection ...✔️

[Jeremy Harris]

4 minutes ago, AnonymousBosch said:

Eye protection ...✔️

 

And gloves...

[ToughButterCup]

Anna hat ✔️

[Carrerahill]

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 August 13, 2019 by Carrerahill

[Jeremy Harris]

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.

[SteamyTea]

Why do you need to use unthickened bleach?

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

[Jeremy Harris]

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.

[SteamyTea]

 

1 minute ago, JSHarris said:

It's the thickening agent

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

[Jeremy Harris]

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.

[SteamyTea]

Thanks.

Thought it may be something like that.

[Conor]

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 August 14, 2019 by Conor

[Jeremy Harris]

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.

[dpmiller]

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...

[Jeremy Harris]

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.

[Cpd]

Well....... it did not go very well, I got some thin bleach but by the time I realised it was not working great it was already to late......... I had a feeling the bleach was not flushing properly through the system so I started again and added some red food dye to the bleach, the top half would then get taken into the system but the lower half remained in the filter in what can only be described as still water. I assume that  the bleach was not mixing very well as it was heavier than the water and / or was because of the jumbo filters and the water lower down just did not get pulled up. Anyway what should have been a quick job ended up taking most of the day......... cutting a very long and boring explanation-short  I eventually got the whole system filled with red dyed bleach water and let it sit for an hour, I then spent the rest of the day flushing the system out until the water ran totally clear, I then made up a batch of blue dyed water and ran that through the system until I had blue water coming out of every tap, then I flushed this all out until nothing but clear water remained.......  you need to remember that this system services three buildings and a cabin..... so lots of running from one building to another....... anyway the moral of the story is to CHECK beforehand that the bleach is readily mixed with water...... due to the way my system works  I am confident that everything is flushed out and even went up in the loft with a torch to check the header tank as I was concerned that the bleach may have settled in the bottom below the take of point. But it was fully clear. What a bloody palaver. The photo shows how the first half of the red bleach gets taken but the second half just sits there....... this could have been very dangerous if I had not been a bit suspicious as you cannot see if the bleach has dispersed without the dye.