There are so many ways to prevent your fish from getting disease and bacteria infections. I would suggest doing the following ;

Don't over stock your fish pond, don't over feed them in the pond, always clean out debris from your fish pond, change the pond water very often and makes sure they are healthy in the pond.

There're are some antibacterial or antibiotics and anti fungi that need to mix to your aquarium to avoid that. I had the same problem before with my flower horn fish, one of my flower horn fish die because of bacteria.

oh. Really. Do you remember what is the name of the antibiotics>

Adding salt to your fish pond or fish tank would help to prevent both diseases and parasites in one's fishes. Please remember that it's not ordinary salt that needs to be added to the fish pond or fish tank, so be careful with the salt you are adding to the pond. I would recommend using aquarium non iodized salt.

@Martinsx You have a very good point with that statement on how effective the use of salt is in treating as well as preventing fish diseases and parasites. When you realize that there are parasites in your fish, a proper salt bath would handle the problem. I have lots of friends that own fish ponds, they always make use of aquarium salt to manage their fish pond and use it to treat and prevent disease in their fish pond or fish tank.

There are many treatments you can add in the fish tank, I add methyl blue in the water every time I change it, it helps to clean the water for any disease.

I think the basic way of prevention is having a well maintained filtering system. This helps a lot when it comes to preventing diseases because we all know that space is an issue specially with small tanks. I have a friend that have an isolation tank, where he keep some fishes with symptoms of disease. This way he can prevent it from spreading to all the fishes in the primary tank.

You should be very careful about water inside your fish tank or aquarium. You should always take care about pollution in the water. You should also install a filtering system in your tank/aquarium. Non-iodized salt can make water clean, remove pathogens, and prevent disease in the fishes.

I just use a bit of Methylene Blue with every change of the water. I reckon for the most part that is about all you need to use.

I think there are some fish that you can try to raise there, like Koi,Crucian carps,red shiner (Cyprinella lutrensis),Peppered corydoras (Corydoras paleatus)

I believe the proper place to raise fishes should be the pond than a tank.it makes the fishes developed better.koi and goldfish do better in a pond.pond water are nutrients rich water where the fishes ca
n feed on algae and other organisms easily.

Oh thank you! I know pond is more healthy but speaking from past experience, I would need to learn more about how to take care of my fishes and the pond. I dont want my fishes to go dying again

If the pond is in good shape and generally healthy to keep the fishes alive and well as you breed them, I'm very convinced that it can be effective for the job. But when it's not in proper shape, it's most likely to affect the fishes negatively which might result in mass death of the fishes.

Thank you so much. It rained so much before and killed my fishes. That is why im concerned

I think the koi and carp fish are applicable fish for pond, I wish I have a place to make my own pond also.

Too bad I don't have any pond at home. I can just have my small tank for now. I think you should try raising your fish in a pond. It's a lot bigger space for them. But you must clean your pond first and equipped it with the fish needs.

If you can maintain and take care of the pond, I don't see anything wrong with it. Your fishes health matters the most, so anything that would compromise their health and survival, it's best to eliminate such factors or variables.

I never have had a pond in my garden, however, I always had this desire to build a pond in my front yard and have some fishes in the pond. Since I lived most of my life in they city where land was limited, I could not build a pond. Now that I live in a countryside I am thinking to build a pond.

You can still raise fish in the pond, clean it well and put there new and healthy fish, actually this depends on what you wish to do because you can also have the option to buy a fish tank.

That was bad to hear. Anyway you can start over again. Raising and taking care of fish is stress free and relaxing.

I feel sorry for the fishes that had been killed in monsoon. You are so lucky to have a pond in the garden only few people can have that privilege. Moving on, I think you can still raise fishes in the pond with daily maintenance and cleaning. The fishes will surely survive in a clean and
healthy environment.