The toads are only in your pond to breed, not to eat the fish. They do make a lot of noise and splash a lot, so it's possible the fish are intimidated by them especially since the pond is new to them, too. My guess is they're hiding, but soon the toads will be gone and you'll have a pond full of tadpoles.

Continue with the air! If your pond is healthy again (check ammonia since there were dead fish) I would put the koi back in if there's plenty of oxygen. Often, the stress of being in a smaller tubby tends to do them in. Foam on the water is usually a sign of protien, either from spawning, or the skin slime of dead koi (or anything dead, like frogs, etc) Get some healthy bacteria and add it to the pond as well, to get everything back to a healthy balance.

Yup. Normally new foliage would grow from the tips of the fork or the cleft in the center of the fork. If you prune below the fork, you give it no choice but to grow from the sides of the existing stem. It will start sending out new shoots all the way around the stem trying to find one it likes, and by that time you'll have gone from one stem with a fork to a half dozen stems radiating out from the center. Here's pictures of one I did it to back at the start of the season (it had finished, so I cut it back to start making a bonsai out of it, its leafed back out since these were taken): I cut that one back to a single straight stem a couple inches long, and you can see how much it bushed out. In fact, if you look at that side view, you can see the original topping there in the middle, its the thin one thats browned over right in the middle.

Thanks for the comments everybody. Only the dorsal fin is clamped to the body. I have tried to catch them, but with no success so far. They just scoot away as though nothing is wrong. I checked them this morning and although lethargic, are still alive. I carrried out a major water change yesterday night after AJC's comments and hope this will help. I have also stopped feeding them. Hopefully another water change on Tuesday will see a reduction in nitrite levels. I was also going to ask the question that Alison has posted. I have no pond salt at the moment. Will "Saxa" do in the short term? Will nitrite poisoning cause permanent damage to the fish gills or can they completely recover? This has been a real learning curve for me. After following "advice" and cleaning the pond in May and getting a giant nitrite spike, I have learned to choose my time more carefully. Also I assumed that as the level of nitrite went down the effect on the fish would decrease. Therefore I did not do enough water changes, preferring to let the pond do it naturally! I think this is now wrong. If anyone else has a nitrite problem, then do whatever is necessary as quickly as possible to reduce it to zero. I only hope that in going through this learning experience I will not lose any fish. Yours worryingly John TW16