[Sneaky]

Hi there,
if you dumped n cleaned your whole tank, you will now need to re-cycle the tank. This will cause more stress on already possibly sick tankmates. This is a solution I would never recommend except in the most extreme cases.

There are many types of "bacterial infection". Melafix is a superb product, but it is mainly used to Prevent infections in new wounds, it is not a medicine per say and so cannot be expected to work like one. If used properly for the right kind of illnesses that Melafix is designed to treat it works very well. Melafix can be HIGHLY Toxic to fish in large quantities. It is a Must to change 30% of the water after every 4th treatment - I recommend this when treating with any medication to prevent toxicity as well as keep water as clean as possible.

For treating bacterial infections that are real bacteria (not fungal), I would recommend the use of the products Furan 2, or Maracyn 2. Tri-sulfa would not be a drug of my choice in most cases since it also destroys the live bacterial colonies in your tank and may cause a tank to go through a mini-cycle. Tetracycline is a dangerous drug, it should be used with extreme care. Keep in mind that this medicine can render fish (and humans) infertile, cause extreme birth defects, and may lead to other problems such as renal failure. It should be handled not at all by pregnant women, and with care by others. I would not use this med on any fish you ever plan to breed, present or future. I also would not use it on young fish. There are safer options.

Sometimes, a "Bacterial" infection is actually a fungus ...for most fungal infections, salt, pimafix, or furan-2 all work good. True fungus is best treated with salt baths, or salt dips.

In order to determine what illness you have, you should always post the following info for us to help you:
Tank size:
Inhabitants:
PH:
Temp:
Test results for Ammonia:
Nitrites:
NitrAtes:
Symptoms:

This will allow us to help you choose the best med for your situation....Ammonia poisoning is one problem where the symptoms closely resemble that of a bacterial infection. Nitrite poisoning also may appear to be a disease with fish breathing heavily or gasping, flashing, and seeming sickly.
Its important to list all symptoms + test results to rule out these issues.