You don't say how many fish there are or how big. When there is such a small volume of water there is very little oxygen for the fish. The big ones usually die first. The small one likely had other injuries from crowded conditions and panic. There may be further deaths. I lost 14 large fish like that several years ago. Another 20 survived.

Ccoombs is an expert when it comes to Koi and she is probably correct in her diagnosis but one other option to consider would be Swim Bladder Disease since it is fairly common. It would give the same bulge on just one side but usually the fish would swim with more difficulty, listing to one side or staying either on the surface or on the bottom. The difference is this condition can be treated. That is why I mention it. A partial list of suggestions that could help: "Feed your fish a couple of peas. That's right, peas. Just get some frozen peas, thaw them, and feed them to your fish. A professor of fish medicine at N.C. State College of Veterinary Medicine has done this in several cases with very good results. He thinks that the peas somehow encourage destruction of the impaction. No hard scientific data yet, but it's worth a try. Fast your fish for a couple of days. Withhold all food for three or four days, and sometimes this alone will break up the impaction and return things to normal. Most fish can go a week to ten days without food and be just fine. Periodic aspiration of the swim bladder works very well. Basically, you stick a needle in the swim bladder and suck out some of the air. Not something to be entered into lightly, but does work well. This is not a cure, but a successful treatment. The head veterinarian at the Baltimore Aquarium prefers this method. Partial pneumocystectomy. This is another word for surgical removal of part of the swim bladder. I mention this less as a practical option but more just to let people know that there are vets out there doing X-rays, surgery, general anesthesia, even cancer chemotherapy." I've never had a fish with a tumor but I have had one with a swim bladder problem. It resolved itself with the peas and gentle massage at the edge and lower back of the swelling. this might not help your fish at all if it is a tumor but it couldn't hurt. Some people prefer to cook the peas for a few seconds and then pop out the inside of each pea. Throw away the skin of the peas. It is tedious but my fish love them. Here is a link that might be useful: never stick a swollen swim bladder with a pin! leave that to a vet.

I am sorry you had such a bad impression of the koi show, especially the vendors. I was in and out of the vendor tent all day because I was helping a friend who was a koi vendor there. I saw only one instance of a vendor who was sitting around reading all day. And that was the only one. Our (my Friend's booth) was packed off and on most of the day with customers. When there was no customers looking at fish, we all collapsed into chairs from the exhaustion of the day. No vendor is going to stand in the isles and try to draw customers in, but I rarely ever see a vendor ignore a potential customer either. It happens, but at this show it was only one vendor. I was mostly at the front end of the tent though, and the one vendor who I am aware of was at the back end. I don't know what else was going on down there. The front end of the tent was very busy with customers all day. I have been to a LOT of koi shows, mostly as a exhibitor and a customer and I always end up spending a lot of time chatting with the different vendors. I have never found them to be cliquish. By that tome of day, vendors may seem stand-offish, only because they are exhausted from dealing with customers all day. I'll give you an example. My friends were selling some tiny koi for $3 each. She spent at least an hour picking out his 20 or so teeny fish. He was happy and left. A few minutes later, he returned with his wife. She didn't like one of the yellow koi he had picked out. So my fiend opened the bag, picked out the offending yellow fish and asked the lady to select another one. 15 minutes later, wanna guess which one she picked? The SAME KOI she had rejected only a short while before. After a long day with customers like that, you are exhausted beyond belief. Like I said, I am sorry you didn't enjoy this show. It is really one of my favorites though. The quality of the vendors, the quality and number of the show fish, and the host club are all beyond outstanding.

Hi Jill, if you haven't already, looking online or at nurseries really gets creative juices flowing. I love koi ponds with small trees and green and purple bushes (personally). Please share photos when you're done, I for one would love to see!