Any Chemists on here?

[Frisbee]

Would anyone know how much Potassium Permanganate I need to put into 40 gallons of water to keep it sweet?

In my field I have no fresh water supply.....well I've got a river running by, but it's not easy to get any out, so I collect rainwater from the roofs of my hen huts and every so often put some PP in. I've never been able to find out the correct amount. I asked the Pharmacist where I bought it from, who did a quick calculation and announced I needed 1.5lbs per 40 galls I kinda figured that that was way too much and have got by using 1.5 teaspoons. I completely ran out of water during the dry spell in summer, but now of course my tubs are full again (and frozen) I would normally keep a bit of a lid on with fine nylon mesh underneath, but I have failed miserably to do that and as it is thawing out and I'm getting the odd bucket out, it's a bit stinky, so I need to syphon some into a fresh tub and start again. I could carry on with my 1.5 tspn but would also quite like to know the correct amount.

Thanks in case........

Frisbee

 

[darrenperrett]

Hi Frisbee.

http://www.travelhealthzone.com/away/water/5-purification.php

There`s something about pp at the bottom.

 

[Frisbee]

Thanks......when I was looking originally over two years ago, that was the only reference to dosage I could find. The words crystal threw me as what I bought is a fine powder, but my 1.5 teaspoons was the amount which tinged it a light pink. My main concern is that I could be using too much.

Frisbee

 

[jimbeekeeper]

Dont get to bogged down with technicalities (although we await the chemistry lesson from others!) just add it until it is a very faint pink.

I would drink it!

 

[Hombre]

The figure for human drinking water is 1.1mg per US gallon
That would be 1.1mg x 1.2 = 1.32mg Potassium Permanganate per UK gallon.
(1 imperial gallon = 1.2 US gallons)

This US site is where the image was taken from.

For verification, see Application rates: Human drinking water. For chickens you don't need as much.

Observe safety precautions as concentrated PP can burn eyes and skin and swallowed or inhaled is extremely poisonous.

Don't spoil him

Oops - I totally agree with Jim.

 

[Hombre]

Sod it Jim, I just read too many books with chapters that have another chapter three times as thick saying "proofs of the other chapter" - I never did understand them by the way.

Not at all a chemist and my first thought was faint pink, but my knowledge is from washing vegetables in distant lands 50+ years ago. I assumed that a more scientific answer was called for.

Besides, it sounds like the water source might not readily show the colour. I don't know if Frisbee takes a tumbler down the field and whether it might be tainted by a bit of cheeky red.

 

[plumber]

try this pdf file

http://www.epa.gov/ogwdw000/mdbp/pdf/alter/chapt_5.pdf

 

[hedgerow pete]

I have used pp for many years for many uses but for animal water it would be around 0.5 part per thousand which is one gram per litre so for a barrel of 50 gallon sive (220 litres) you will need 110 grams

 

[Frisbee]

Thanks for the replies, including the humorous ones

I carry any water in a white bucket so can see the pink tinge, it's the colour I went on in the past which brought me to my 1.5 teaspoons. The pink goes brown after a few weeks.

I have a proper teaspoon measure and always wear gloves and am really careful when handling it Hombre thanks.

Frisbee