My local Thin Bleach is <5% Sodium Hydroxide is that OK?

[chem geek]

Though I'm away from home, it REALLY seems like all those Clorox containers say something like "<6%" as well, possibly because if it degrades over time that's all they can guarantee?

As shown in the chart at the bottom of this page the half-life of chlorine at 5% at 75ºF (24ºC) is 1147 days or over 3 years. Essentially, low concentrations of bleach kept at room temperature take a long time to degrade. Here in the U.S. Clorox Regular says 6% as do many off-brand Ultra bleaches.

It is certainly possible that Clorox decided to make only weaker bleaches in the U.K., but they certainly didn't have to do that.

Also, there are quite a few manufacturers of chlorinating liquid at 10% and 12.5%. In Europe, Purex is one such brand of higher concentration chlorinating liquid. In the U.K., Tesco seems to use the vague "< 5%" approach. This link implies that you can buy the more concentrated chlorinating liquid at pool stores so you should compare that pricing against the far weaker bleach available in other stores.

 

[Kes]

Hi Langey (and everyone),

Sorry about coming late to this thread, I'm not a regular visitor during the winter months. I had exectly the same problem: decided to use bleach instead of tabs, assumed that <5% meant 5%, ended up with a green pool. I use Tesco bleach which I have roughly tested by dilution to be around 2% Sodium Hypochlorite. That's fine once you know what the strength is. I usually add two x 2 litre bottles twice a week on a 11,000 UK gallon pool (we don't get so much sun here). During the season that is.

I find that using Tesco (or similar) bleach is, % for %, cheaper than the stronger liquids available from pool stores. I would far sooner use a larger quantity of weak bleach than struggle with a large container of more potentially harmful stronger bleach.

 

[gbobbage]

Hi all,

Just started experimenting with bleach this past couple of weeks, things are a little different here in the UK as Kes says, household bleach is sold at <5% Sodium Hypochlorite. So to add onto the list ASDA bleach seems to be WELL below this level (may be <2%?). I will try and test several types and post back here after putting a few ml's into a bucket of water.

I have just spent £23 on 20 litres of 14/15% this morning in a pool shop, this is probably expensive but if you only buy one container shipping is pricey here.

Afterwards I had a little dig round and found that what I should have done is bought a product called "Red Label Hypo" it's used in the dairy industry but the data sheet here http://www.johnsondiversey.com/wcmt/ProductAttachments/en-GB/PIS/P91390GBENC-01.pdf and the MSDS here http://www.jfmckenna.com/business/Image/PDF File/Mushroom/MSDS/Deosan Red label 2005.pdf Shows it to be 11% available chlorine Sodium Hypo!

I phoned our local SCATS countrystores who didn't know what Sodium Hypochlorite was but had 9 x 20L barrels of "Red Label Hypo" in stock at a staggering £8.04 each (Don't know who manufactures it)!!!!

Has anyone (in the UK) tried it yet? TESCO and ASDA sell thin bleach at 14p a litre but if it is as weak as we reckon then this "Red Label Hypo" stuff is a bargain at the price and even the datasheet says it can be used for swimming pools!

Cheers for a great site!

Gareth

 

[chem geek]

Welcome to TFP!

And thanks for the great tips on finding chlorinating liquid in the U.K.