Water storage project

[jansman]

All of the above is valid. I store water in 25 litre drums. In the dark on a cool brick floor of an outbuilding. I rotate it maybe once a year. When I do, I bang in a cup full of thin bleach and leave it half an hour. Then I tip out the water and refill, without rinsing inbetween. Works for me.

[ForgeCorvus]

Bleach degrades over time and loses its "Bleachiness" so you will need to rotate stocks if you want to hold some for future water purification. I have read that swimming pool granules don't degrade and can also be used but I don't know whether this is true or not - can anyone confirm?

.

Correct, Sodium Hypochlorite is the stuff they make bleach from and will store for a long time without losing its 'poke' like liquid bleach will.
Search for "Pool-Shock" or "Hypershock" as well as the chemical name.

You'll need to dilute the Hypochlorite with water to make the bleach that you can then use normally..... I'm not sure of the dosage ATM, I need to dig the details out

[featherstick]

Many thanks Corvus.