We went through substraits, rocks, aquaculture so lets talk about water. There are two choices, ASW ans NSW. I prefer natural but I know most people don't live on the sea. ASW is a good substitute and it seems that fish and corals will live fine in it so I doubt that will change much.
So lets discuss diseases. I feel that fish should not get diseases so we don't have to spend time cureing them. Fish in the sea almost never get sick, because of their immune system. Fish have an amazing immune system, better than ours because the sea is an extention of the fishes circulatory system. Whatever is in the water is in the fish just like whatever we breathe is in us. Every nutrient, chemical, pollutant, virus and bacteria on earth is in the sea, but not in the air we breathe. That is why a fishes immune system is go great. But it only stays great through the proper food. We fail miserably when we feed our fish and try to give them what is easy for us to get but not necessarily the best thing for the fish. Just because they eat it, doesn't mean it will keep their immune system working as good as it needs to. My moorish Idol would eat newspaper if I put clam juice on it.
Fish in great condition spawn. All fish spawn or at least get in spawning condition so that if the conditions were right, they could spawn. A fish must be in it's best condition to spawn because developing eggs is a huge burden on a fish. Eggs could take up a quarter of a fishes weight and they are mostly oil. Most fish have enough trouble just trying to stay alive. If the fish are not in spawning condition, their immune system is not hardly working and they will most likely get sick and have a short life.
My fish don't get sick. "Almost" never and I don't have to quarantine. They also live a long happy life unless they decide that they are so happy and healthy that they jump out. Sick fish don't jump out much because they don't have the energy but healthy ones do. Jumping out is not a sign of sickness, but it could be a sign of health so I don't count jumping out as a fish lost to disease.
My oldest fish now is 18, it is a fireclown and he is breeding.
Most of my fish live forever except for the jumping thing. If a fish gets to large or mean, I give it away either to a hobbiest of a public aquarium.
Anyway, my thoughts on disease is that fish should not get diseases so we don't have to worry about curing them.
I believe that the future food will contain sufficient oil and other nutrients to match the fishes natural diet so that it stays in breeding condition and we can let it's immune system take care of diseases like it is supposed to do.
I have been thinking of an artificial worm. Something like the thing a baker uses to write on cakes. A food could be put in a device that will compress it and it will come out in the tank in long thin strands that resemble worms and have the same nutrients as worms. Most fish should recognize this as food as most fish will eat worms. I feed live blackworms every day and IMO that is the key to keeping the fish in breeding condition so it's immune system will ward off most diseases. I can't think of any other reason why my fish don't get sick. I doubt it is my UG filter.
This "worm" making device could be programmed to dispense "worms" throughout the day in the manner that fish are suposed to eat, all day, not just once or twice.
We have live worms that I said many people can't get and we have frozen mysis. Mysis are an excellent food that incorporate calcium and oil but they unfortunately have a large portion of substance as indijestable shell and head parts with very little meat.
Now remember I am not the God of fish food, rocks, mysis, worms or anything else so does any one have any comments, good or bad?:strange: