Man forgot to turn off the water!

Question
Please help.. Hopefully not to late. Boyfriend was adding water to the pond and forgot to tun it off.. It ran 12-24 hours 1500 gallon pond. Have lost 7 fish already 4 goldfish, 3 kois.. I am devastated. We put in Stress coat for the chlorine last night. I added some salt, probley not enough, maybe half of what the box said... Yesterday it was two goldfish, this morning there were 5 more dead. I know night time is the worst.. I told boyfriend to go and buy another pump to help circulate the water and give more oxygen. 7 or 8 of my big Kois are at the top swimming very slow. What else can I do to save them? I'm sure the tempature was close to 80 before water change, now I am sure it's close to 60... I am so sad... I will buy a water shut off thing so it never happens again.. I told him to not touch the pond anymore.. Please help! I don't want to lose anymore!

Answer
Im sorry to hear about your pond and your fish loss.  I would actually change the water out and add in warm water if possible along with a dechlorinator.  I would also add in pond bacteria to help control the water chemistry... The biggest concern here is the drop in temperature.... You will want to be prepared to treat the pond for ICH... which is ually set off by a drop in temperature.  I would also add some additional salt to the pond... The fish that have survived will probably be ok... but you do want to watch for sighs of ICH.... I once forgot that I was filling a fish tank up andkeep me posted... dave