How To Properly Treat Fin Rot?

[KrystaK]

I've had three of my four rescued guppies die of fin rot in the last 3 days. I didn't know it would work so quickly

Today I bought Mardel brand treatment (It comes with a pamphlet on how to diagnose fish diseases and everything, I'm very impressed with it)

So I put that in my hospital tank in hopes of saving the last girl I have. I haven't put any salt or anything else in the tank. Is there anything else I could do to improve her chances? (I feel bad that I could only make the others more comfortable, and not save them )

 

[B Rolls]

I just got over fin rot in my neon tetras. For me the ammonia was causing the rot and it ended up being my filter. It was under performing. I bought the biggest hang on the back the store had and it went away in a week. What is your ammonia level? Oh and btw i had a case of fin rot before I found it was the filter and I used melafix and it did ziltch.

 

[KrystaK]

My ammonia readings are between 0-.20 ppm, which are the lowest readings on my indicator, so I assume it's fine.
I do have a high pH but I don't know if that would affect anything.
I was assuming it was stress from being moved from my friend to my home tank and then to a hospital tank when they didn't get better.

I've heard good reviews on the Mardel stuff, so Im hoping it works. I just got 2 more guppies (My friend is way over stocked so I'm taking some of her fish)

Anyways, if she survives the night I'll be impressed

 

[B Rolls]

If the tank in the picture is the tank in question. I would first test the ammonia. If it is over 0ppm, it may be your fliter, because your filter looks like the same one I had, an aqueon 125gph. I bought an aqueon 55/75, but the tube is too long to fit in a 30, so I would either get a tetra whisper 60, or a marineland penguin 350. You can pick the marineland one up at petsmart for around $40.