Help major disease problems!

[otter]

Okay this isn't about betta, but it is very important.

Whenever I buy guppies from petsmart, One of them has fish tb and wipes out the whole tank to I have to start over.

I treated the tank with kanamycin and for a few month everything looked fine
but today I noticed that one of the guppies was really pale and wasn't really playing with the other guppies.

He would kind of hang out to the side of the tank at the top away from all of the other fish


He doesn't have a curved spine yet, but it looks like it may be starting

I stuck him in a jar, but he is actually really active. When all of the other fish that had tb were in the tank they would be really inactive, but he is super frisky.


Does anyone know if this is tb? or am I just over reacting?
I realllyy dont want the whole tank to have gotten it


edit: He also has a really thin tail. All of the other guppies have thicker tails but it looks like his tail is really thin and it kind of looks like its deteriorating

[otter]

Here are some pictures of him.

As you can see, he is really pale.

The other spotted guppies ive had are super bright yellow with dark spots

[FiShFiShFiShFiSh]

Just because he is pale doesn't mean he is sick, it could just be his natural coloration. Unless, you have seen him at more coloration, and noticed that his colors have faded over time. So I wouldn't worry about that. However, you said that you have been having a problem with TB wiping out your whole tank, so I have one piece of advice: quarantine, quarantine, quarantine! :) Every time you want to introduce a new fish to your tank, make sure that you keep the fish or group of fish in a separate tank for at least 2 weeks, but longer is better. Make sure you see no symptoms of any sort and they will be fine to add to your main tank, and you will have no more disease problem! He appears healthy to me, but if you say he is appearing frisky and super active, he may have some sort of parasite that isn't visible from the picture. If his movements are spastic, or he appears to be darting and attempting to scratch himself on something, then there is a high chance he has some sort of parasite.