I did the same thing over last winter.... lost all around 10 koi, 2 commets,
1 goldfish and like 2 mosquito fish before I caught the error... I put in
declor.. (mine treats 7600 gallons per bottle) and I had a goldfish survive
(I was pulling him out as deceased when I saw his gill move) and a baby
koi/goldfish mix along with a couple hundred mosquito fish. After that I
name all my fish. I have Lucky, his brother Lucky, his wife Lucky there 362
kids all name Lucky...... and George. So... from what I understand about
chloromines is that it prohibits the exchange of oxygen as water passes the
gills. It apparently doesn't damage them to the point where you will lose
all your fish if you treat the water quick enough. If your neighbor is like
me tell him not to be too hard on himself and make some offerings to the
pond gods.

"Randy" wrote in message
news:3zwIc.74815$XM6.22733@attbi_s53...
LAst night my neighbor was topping off his 7700 gallon pond and he
accidently left the water on overnight he lost about 25 of his 50 fish. I
dumped in some water prep this morning but I wonder if there is something
else I can do to save the remining fish. The whole pond is new water
now.Please help.