Phyllis and Jim Hurley wrote:
You know, a couple of days standing or a half day of good circulation
should take care of the chlorine without any treatment. Up to 10%,

But not if there's chloramine as well (AFAIK).

slowly added should be totally a non-issue, especially if there is good
circulation.

Jim

Bill Stock wrote:

I just bought a 5 lb pail of Sodium Thiosulphate for the
pond/aquariums. The instructions I have read here in the past suggest
that this should be enough to dechlorinate lake Superior. But reading
the bucket, it states that I need anywhere between 1/4 tsp and 1 tsp
of raw ST per 5 gallons of pond water. This means that a 250 gallon
water change would take up to 50 tsps. Given that the bucket only
contains about 5 cups, that's 10 water changes.

The stuff in the bucket looks like some sort of crystal, not a powder.
Has this stuff been bound with some other chemical to reduce it's
strength? At this rate it's no cheaper than the generic slime coat.
Bummer.