Please Help! New Guppy Has Cottonmouth/mouth Fungus!

[PrincessKiara]

Hello all! I'm 16 years old, I LOVE fish, and I have had a 28g tank before, but I had to switch countries and leave my babies behind in the care of a friend. :'( Now, though, I'm finally getting another tank, a (thankfully, already cycled) 63g, and I'm super excited! I'm getting it and setting it up this weekend.
Anyway, I need some help. I just bought 4 guppies (2 for me, 2 for my friends) and have them in my quarantine tank (which is admittedly somewhat small, but they'll only be in there a few days). They looked fine at the LFS earlier today when I bought them, and the smaller female (mine) popped 11 babies on the way home. The males are the most gorgeous guppies I've ever seen and are very active; the babies seem very active and healthy despite being in a small jam jar (which is all I had to put them in; I wasn't expecting them so soon LOL), but the larger female (my friend's) has what I suspect is cottonmouth (white fuzz on her lower lip) and is not moving around much. (I haven't seen any of the adults eat, though the fry are eating; but then I haven't paid too much attention.) I know I floated them properly for 15 minutes before dropping them in their new home, and like I said, except for that female they all seem fine.
Anyway, tomorrow I have to take the fish to my friend, and I need to know how to help her! Is it safe to swab mercurochrome or hydrogen peroxide onto her mouth to disinfect it? Or would adding methylene blue to the water be better, to prevent infection in the others as well? But would that harm the fry or the Elodea plants I have in there too? Please help!
Thanks in advance
~PK.

 

[PrincessKiara]

Anybody? Can I put mercurochrome on her mouth? I read somewhere that should be done Unfortunately I can't take her back or get aquarium salt, and she was with the pregnant guppy and the other two when I bought her. I don't want the baby fish to die! Or the adults for that matter! Please help :'( Mercurochrome and methylene blue are all I have.

 

[TwoTankAmin]

It is bacterial and needs antibiotics to cure.
 

 
Mouth Fungus
   Symptoms: White cottony patches around the mouth.
   Mouth Fungus is so called because it looks like a fungus attack of the mouth. It is actually caused from the bacterium Chondrococcus columnaris. It shows up first as a gray or white line around the lips and later as short tufts sprouting from the mouth like fungus. The toxins produced and the inability to eat will be fatal unless treated at an early stage. This bacteria is often accompanied by a second infection of an Aeromonas bacteria.

     Penicillin at 10,000 units per liter is a very effective treatment. Treat with a second dose in two days. Or use chloromycetin, 10 to 20 mg per liter, with a second dose in two days. Other antibiotics can also be effective. Kanacyn (kanamycin) will treat both bacteria at once. Maracyn (erythromycin) is effective against C. columnaris, and using Maracyn 2 (minocycline) in conjuntion with it will treat the Aeromonas bacteria as well.

from http/animal-world.com/encyclo/fresh/information/Diseases.htm#MouthFungus

 

[PrincessKiara]

Thank you

But does methylene blue work? That's all I have, and unfortunately I cannot separate her from the other fish. I mean, I bought them together, so they're probably infected too, but they are showing no signs of illness yet, thankfully. I was able to take her and one of the males to school, though, and my chem teacher (who also keeps fish) put in enough methylene blue to make the water a deep blue and says that will cure her, but I'm concerned about the plants. And what if it doesn't work?

I also brought some home to put in my fry jar and my quarantine tank.