How To Remove All Bacteria And Parasite Problems

[Photobelle]

I have had a lot of fish die. Yes my tank is cycled. I have treated for parasites and bacteria. I do not know if it is tb or something else and not all fish would have the bent spine and sunken belly. How can I treat or clean my tank of everything before adding new fish? I do still have 4 glofish danios, a snail and some shrimp. I also want to get rid of my pest snails that have gone crazy so if there is a way to do that as well great. Do I have to completely break it down and clean it all, etc? I have sand so I am willing to toss that and get new. I don't want to buy fish that are going to keep dying and I'm undecided if I want to try and remove the problem whatever it is or just trash the tank. Thank you.

 

[A201]

The best medicine for aquarium fish is prevention. Water management skills are paramount. What it comes down to is easy, but requires a little work. A weekly 50% WC and being very careful not to overfeed. That will go a long way towards a healthy tank.
The snail population should sharply decline if excess food isn't allowed to settle on the substrate.
Be sure to research the particular future fish you plan to stock. Some fish are more resilient and disease resistant than others.
Everybody has had aquarium disasters at one time or another. Hang in there, things will get better.

 

[Zka17]

How big aquarium? What filtration? How long after purchase the fish started to die? What are the water parameters?

I sincerely don't believe that you can completely eradicate bacteria and parasites in an aquarium... You just have to find fish which will fight them... - keep the nitrogen cycle and keep the water clean.

I would start with the water changes, then if the fish keep dying, then think about medication.