Lt. Kizhe Catson wrote:
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.





Chlorine and chloramine tend to react with any organic molecule they
encounter, oxidizing it. Cloramine is stable to sunlight and aeration,
but nearly as reactive as chlorine. It's actually very similar in
reactivity to potassium permanganate. Ponds and fishtanks have lots of
dissolved organics, bacteria, and sludge around so small doses of
chlorine or chloramine don't last long. A 10% water change worth of
chlorine would be gone pretty quickly even without the sunlight and
aeration in a typical pond.

Small amounts of either chemical in fishtanks and ponds can actually be
a positive thing, promoting a healthy oxidizing environment and lowering
parasite and bacterial populations. Chloramine T in particular is safe
enough for fish and filter bacteria that folks have tried it for
treatment of bacterial gill disease in aquaculture and for external
parasites and flukes in pond fish.

http://www.fishdoc.co.uk/treatments/chloramine-T.htm
http://afs.allenpress.com/afsonline/...ssue=1&page=63

So, I guess I'm saying don't sweat chloramines in small top-offs either.
I tried putting in up to 10% of fishtank water without treatment after
I first saw the aquaculture studies and have yet to see any fish stress,
even with my loaches and ram. I also tried not treating my last rwo
pond top-offs as well (about 7%), and saw no signs of toxicity when the
fish ate later in the day.

--
Elaine T __
http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com