measure % hypochlorite?

[engrav]

greetings

so have some $2.49 / gal bleach from local Do It Best?
no label on the bottle as to % hypochlorite

can I / how might I measure this?

 

[jblizzle]

Not easily or accurately. There are a few thread that discuss how to estimate it you can search for.

But, generally if it does not say, it is probably around 3% at most.

 

[engrav]

Not easily or accurately. There are a few thread that discuss how to estimate it you can search for.

But, generally if it does not say, it is probably around 3% at most.

so I called Do It Best
they said call Champion
so I called Champion
they said "let me check as we send 3 and 5.25"
they came back and said "we send Do It Best 5.25"
so maybe, but then maybe not

I suppose could
1) buy a bottle of generic and Chlorox
2) pick a cloudy day
3) dump a gallon in a particular spot where circulation seems weakest (NW corner of shallow end)
4) measure FC in the same spot 1 hour later
5) pick another cloudy day
6) dump a gallon of the other in the same spot
7) one hour later measure FC in the same spot
with skimmers / heaters etc set the same

 

[techguy]

I would say to assume unlabeled bleach is between 2-3% and move on. I would suggest buying LC bleach at WM or HomeDepot as the inventory moves faster and you know is not been sitting on some loading dock for a year waiting to be sold at the dollar store. I have never seen the bleach at such a discount be worth it once you consider it's strength ao lack there of.

 

[JasonLion]

The most reliable test is to add 6 or more ppm of chlorine, based on your assumption of the strength, and then see what happens after it has a half hour to mix in with the pump running. That won't reliably distinguish between 5.25% and 6%, but it is more than enough to distinguish between 3% and 5-6%.

 

[engrav]

The most reliable test is to add 6 or more ppm of chlorine, based on your assumption of the strength, and then see what happens after it has a half hour to mix in with the pump running. That won't reliably distinguish between 5.25% and 6%, but it is more than enough to distinguish between 3% and 5-6%.

the 2.49 bleach is sooo convenient out here in the woods that I think I will try this
if it comes up about 5, wonderful; one pool problem solved, if not am not out much
can even order online and pick up at the nearby hardware store (they do not stock pool volumes)
and 6 to 12 would be 3gal1qt; not an expensive experiment
but the grandbabies are here this week so will wait till next, or next

thank you

 

[techguy]

Restaurants frequently use bleach in the dishwashing process, You may find sources for restaurant supply have stronger bleaches/chlorines in cost effective containers.

 

[Kes]

Or use the dilution and test method, as set out here measuring-bleach-strength-t28650.html

I would use the low strength bleach, if it suits you. I use Tesco's thin bleach, which used to say under 5% sodium hypochlorite, but now says 1.5% s/h, which I suspected. I don't know of any stronger, labelled, uncontaminated, freely available supermarket supply in the UK. I have to fetch and carry more, but I have low chlorine usage, about 8 litres of this stuff a week. It would be hopeless trying to shock with this.

Higher strength bleach is available from pool suppliers, but the weak stuff has the advantage of being far safer to handle, you could almost drink it. It's also cheaper overall, at 29p for two litres.

I have tried commercial cleaning suppliers 10% bleach, once but not again. You just don't know what's in it. It's made for cleaning, not pools.

 

[Kes]

Me again. One of the older bleach strength testing treads is this commercial-bleach-testing-concentration-t10789.html where JasonLion dilutes 10 ml of bleach with 1 litre of water, giving a dilution of 1 to 100. This is not the same as 1 in 100: as you now have 1010 ml litre of fluid it's 10 in 1010, 1 in 101. So a reading now would be 0.01% low.

The next dilution would compound the error. Instead of the 10 ml containing 1/100 of the original bleach (0.1 ml), it holds 0.099 ml. After dilution with 1 litre it's 0.099 in 1010.

My head's beginning to show signs of strain, but I think that's an under-reading of 2%. All that effort for a measly 2 percent. I need to do something else now.

 

[engrav]

The most reliable test is to add 6 or more ppm of chlorine, based on your assumption of the strength, and then see what happens after it has a half hour to mix in with the pump running. That won't reliably distinguish between 5.25% and 6%, but it is more than enough to distinguish between 3% and 5-6%.

ah ha, do not need to measure; ordered some bulk and bottles came in a box
nothing on the bottles but on the box says 5.25
so another PP (pool puzzle) solved