Sick fish tanks

Question
Hello, I have kept fish for many years. I have been fairly lucky with illnesses but recently I am having a problem in two fish tanks that are near each other. Both tanks have been set up for three years. The first tank is a 20 gallon. pH is 7.6, 0 ammonia, 0 nitrites. I only have three female bettas and one zebra danio in the 20 gallon. I do water changes every week about 30%. All fish have been in this tank for about a year. All were healthy got along great until about 3 weeks ago. I first noticed that all of the bettas started to rest more and were bloated. I used spectrogram suspecting an internal bacterial problem, although I had no success. Then the three girl bettas and the danio seemed to have a hard time eating their food, it was as if all of a sudden the food was to big for them and if they did swallow a piece it would appear as if they were coughing and cough it out. They seemed to want to eat badly but just couldn't. Then clamping of the fins started and now none of the fish will eat although the fish are not bloated at this time. I then did a large water change, tested the water again, it was good. Ran the carbon for a few days and then took it out again and tried Paragon II. Again nothing. Fish are still getting sicker and not eating. There are no visible signs of parasites on skin. No visible signs of fungus or redness or ulcers. There is no trailing white feces. Just wasting away, clamped fins and a little darkening of color and the female bettas are resting a lot but the danio is swimming very fast as if he is disturbed, which he normally swims fast but not this fast. Although there is no scratching. All are going to die I fear, but of what? In the second tank is a ten gallon, water also tests the same as the 20 gallon which is good. Awhile back ago I had a betta who also got thin and died in this tank and since then a few guppies got pop eye, and wasted away even though they were eating. I am fearful I may have an outbreak of TB and even though I wash my hands before I touch each tank I am afraid I may have transferred it to the 20 gallon. But I am not sure? I am also worried about hexamita. Although when I lost the betta in the ten gallon I did try metronidazole in the food with no success, I also tried antibiotics with no success. If it is TB I am scared. I had a friend who breeds and lost 27 tanks to fish TB. Although only 2 fish were tested by a lab and it was in fact fish TB. When more then one tank is infected and it you can't seem to stop the disease with any medicine it makes you want to give up on the hobby. It is so stressful. I have other tanks near these two so I am worried about them also. And if you can't find a medication to stop it and you don't know what it is that is killing your fish you pretty much have to tare down the tank. To tare the tank down and bleach and start over is such a pain. Not to mention even though I am a grown women, it makes me very sad to watch them die or to have to put them to sleep. Do you have any suggestions?  Even if you don't, I cannot thank you enough for taking the time to read this. I think what you do to help people with their fish is so very special, thank you so very much.

Natahsha

Answer
Natahsha, I am so sorry this is happening to your fish and it has caused you so much heartache. I know how hard it is to watch our little friends get sick and die. Especially when we try so hard to make them well.

I found an article that may help you. It describes a treatment that includes vitamins. Here is the link;

http://www.nationalfishpharm.com/articles/mycobacteriosis.html

Followups welcome.

At Your Service;
Chris Robbins