ADF frog very skinny and not eating

[Miss Blue]

Hey there! My mother has 3 African Dwarf frogs (I got her into them lol) and the one is very skinny and lethargic and looks so under fed while the other 2 are pleasantly plumo after eating and do have great appetites and are active.
I help my mother isolate the little guy (his name is Ringo) and he is currently in a small aquarium and she has been giving him his own food but he just floats lazily at the top. He was very active but recently became more lazy (weak).
I am going to suggest trying other food as maybe he just doesnt like brine shrimp (if that is possible). aside from his size and weakness everything else looks normal.
The tank she had him in is a fluval edge like I have and it has a great filtering system and I bought her all the proper water conditioner and cycle (beneficial bacteria) to put in it.
I have seen frogs float on top of the water for a long time but that was a frog I had a couple years ago who apparently died from dropsy. Any help/input would be appreciated, thanks

[Miss Blue]

so to totally answer my own question I believe it is bacterial (I did some research). The thing that threw me off was the fact he was so skinny as for some reason I associate illness with only redness and bloat. Im thinking not enough of the old food is being removed and I think bottle water was being used to replenish the tank. I have changed the water and treated it properly and my mother is picking up some bacterial treatment stuff. I am hopful this little guy will be ok.

[LunaDay]

so to totally answer my own question I believe it is bacterial (I did some research). The thing that threw me off was the fact he was so skinny as for some reason I associate illness with only redness and bloat. Im thinking not enough of the old food is being removed and I think bottle water was being used to replenish the tank. I have changed the water and treated it properly and my mother is picking up some bacterial treatment stuff. I am hopful this little guy will be ok.

I hope he is okay too. Trying different foods could help also. My guys love white albacore tuna, shrimp pellets, bloodworms, (I have heard you can give them worms from the bait shop but I have not tried this and now danio feeders! Keep us updated. I will be sending good vibes your mom's way ~~~~~<-----vibes

[Miss Blue]

Thank you for the good vibes it is appreciated but yes little Ringo died def bacterial infection so i helped my mom do a water change, add meds to the main tank (Ringo was taken out when we first noticed something wrong) and I reminded her of treating tap water and doing regular changes (she was only putting in bottle water, not good enough!) I think I am also going to stop using the frozen brine shrimp and stick to frozen blood worms and I encouraged her to do the same as they are easier to clean up. I would def like to try other options so will look into your suggestions on the plus side my tadpoles are doing very well so hopefully I can give her one soon enough!

[LunaDay]

So glad to hear your tads are doing well Miss Blue! You're definitely on the right track