[blam]

I have the ‘pool shock’ chemicals in my ‘disaster’ supplies. I saved bleach in bottles for a while but my son (PhD phyics) says that it loses about 50% strength every year.
The ‘pool shock’ is crystals and apparently maintains it’s strength. BTW, I bought it cheaply at yard sales.

[mountainbunny]

As pool season ends around the country, this is a good time to pick up shock powder on clearance. Wal*Mart almost always has it on deep discount at the end of the season.

[Oorang]

Thanks to you both, very useful information.