Diseases can have a catastrophic effect over the fish community in your Aquarium. They could come from either an improper fish tank installation or if you decide to introduce objects incompatible with your fish fauna. But all this can be prevented if you follow these rules regarding your fish tank environment.
You must avoid putting your fish in a new aquarium, because it is a very difficult job to regulate and properly condition the water in the fish tank. The water needs time to develop some bacteria that will keep the fish tank clean. If you decide you want to setup a new aquarium it will not have time to create the bacteria and very soon the waste in the tank will create ammonia, which is highly toxic to fish and they will all die.
Be careful about the new fish you want to add to your Aquarium. For the new fish is advisable to create a separate tank so they will have time to adjust to the water conditions. By doing this you will make sure the fish does not have any disease and will not contaminate the other fish as well.
Another important aspect you should keep in mind when having an aquarium is not to add to many fish in it. Having too many fish will increase the risks of getting more ammonia and killing your fish. Besides there are some standard rules about how many fish should be in a fish tank in order to keep them healthy and not stress them.
Also try not to feed them all the time and program a schedule for them. The more food you give them the more waste there will be in the Aquarium. More over, if you feed them they will grow and will start eating the other fish in the tank.
