Over medicating fish

Question
QUESTION: My 32 gallon tank is about 3 months old, with a combination of glass cats, a gold fish, a couple of african dwarf frogs, a male beta, a large fan tail and a large black molly. The Molly developed a red sore under her tail which subsequently has left a 1/2 hole in her tail. The pet store suggested Melafix to treat her and advised the whole tank should be treated as whatever she had was contagious. The Mollys sore is now less swollen after treating for 4 days and appears to be healing but she and the beta have become very lethargic and the beta has gotten a whitish siver appearance to the back of his tail and fins. Is it possible I am overmedicating, even though I am following the directions? If not any suggestions?

ANSWER: what is the water chemistry???? I always find it interesting that fish stores tell you to medicate but can not tell you what your fish have... it is their way of having you buy something.  I would stop medicating, do a 40% water change, add beneficial bacteria and watch the water chemistry.  Did you remove the carbon filter from the tank before you medicated... carbon will absorb all of the medication before your fish get any of it. Malafix is a great medication for wounds... but wounds are not contagious... Malafix will also cause your fish to have a whitish slime coat... which is probably what is going on with the betta... Feed them.. .brine shrimp and tubiworms.  This will  help to boost their immune system and help them to heal on their own.  Molly's are live bearers which means that they give birth to live babies... it is quite possible that your molly recently gave birth to fry which is why her tail area is red... is that a possibility???? dave

---------- FOLLOW-UP ----------

QUESTION: I was wrong about the name of my fish, she was a Black Moor about 4-5 inches long. The wound on her tail was quite large but after using the melafix the swelling was reduced and despite the hole, it was looking like she was healing. I did do a 40% water change last night, then I went back to the pet store last night to buy a water kit. After doing some reading I realized the medication could cause the levels to change quite drastically. When I changed the water I added step 2 Nitrite and ammonia reducer as well as the clorine remover. Atthe moment my water levels are: Nitrate 40, Ammonia 0, Nitrite .25 and ph 7.4. No idea where the levels were before the water change.
Unfortunately my Black Moor had passed away when we got back from the store, kind of expected it. The Betta this morning is not eating, lethargic and her tail looks like it is shredded, although the whitish/silver appearance has disappeared.
I did remove the carbon filter before and during the medication period. I am feeding them blood worm, baby brine shrimp, along with tropical fish pellets and veggie wafers for the percosimus (sp). I try not to overfeed and the frogs make sure the bottom is clean. Can you recommend a good bacteria and advise on the water levels? I am hopeful the Betta may recover but the rest of the fish look like they are fine.


Answer
Hi Bernedette:  Sorry to read that your black moor has passed away.  What is the tank temperature???? Betta fish are very prone to bacterial infections and I would treat him with an antibiotic such as triple sulfate.  I would not use the malafix even though the label says it is an antibiotic.  I use CYCLE or NITROMAX as bacterial supplements so those are the two products I would recommend... Everything else looks normal... Keep your eye on the nitrite.  dave