On Friday I rescued 7 koi from an abandoned pond at a foreclosed property. The pond was probably 500 gallon sized preformed plastic but only had about 3 inches of water left in it. The 7 koi range from about 3-4 inches to 9 inches in size- too much for the amount of water in the for certain. Since the property was in foreclosure the water service had been locked off so there was no chance to just fill the pond and leave the fish there. I siphoned a 5 gallon bucket of pond water off and got all 7 fish in it and had them home within an hour. I have a 300 gallon pond built into my deck with my 6 small koi in it. I also have the plastic preformed pond originally for my fish which was still about half full of water. I called my wife from the foreclosure and had her fill the preformed pond and get it ready. I got the rescues home and jist floated them in the 5 gallon bucket for about 30 minutes. By now it was pouring rain so the bucket filled up with rainwater and tipped itself into the pond. The water tested fine so we let the rescues swim into the pond. I was not able to get aeration, filtration or circulation in the small pond at that time but figured they were at least better off than they were in the near empty pond they came from. All was fine yesterday morning (Saturday). I fed both ponds with koi pellets and everyone seemed more than happy to eat. The rescues had obviously not been fed in some time and tore through the 10-15 pellets I tossed in with them in seconds. We were late heading to church so I was still not able to set up any aeration or anything. We were about 3 hours at church then stopped by home on the way to some friends house for lunch and fellowship. Checked on the fish then and all was good. Got back home around 7pm which was just about 24 hours since I first got the koi into the pond. ALL 7 were at the top together seeming to gasp for air. I quickly got out my extra aur pump and large air stone and dropped it into the pond thinking possibly oxygen depletion due to the number of fish. The fish went to the bottom when the water was disturbed but soon came back to the top. I don't have extra filter or circulation pumps but I know my main pond is very well oxygenated and the water conditions are good so as an emergency fix i moved the 7 rescues into my main pond along with the airstone. The rescues seem to be slightly better by this morning buy still come to the surface and seem to gasp. There are now 12 koi in my 300 gallon main pond. The 2 largest (rescues) are 8-9 inches. The rest are all less than 4. I know that is still greatly overpopulated but its temporary until i get enough pond space going for all of them. The rescues are still at the top quite a lot and I'm wondering if this could be normal for them or stress related or what. The largest rescue seems to be swimming with a slight tilt to one side but the rest seem ok except for the surfacing. Any thoughts or constructive advice is appreiated.