How to tell if fin rot is healing

[MommyMelzy]

I have a 20 gallon tank and I have been treating my fish for fin rot using Kordon Rid Fungus. The first 3 days I used 2 tsp, twice a day. I took out the carbon filter and the fish that are effected seem to be healing but how can I be sure? When should I stop using the treatment and should I do a partial water change? Today is Day 4

 

[Matt68005]

I am sorry i meant to get to this.
Tail rot is often caused by bacteria that are not stopped by simple "herbal remedies" or Tea tree oil, or "clean water" (what water in a fish tank is actually "clean????"
This is of course my opinion and i could be wrong to a limited extent, (unless someone wants to put some reference material up where studies have been done. Im sure there is a way to cure certain types of bacteria with only salt and lots of fresh water)
But i like to think of it as, you get sick, the doctor gives you an antibiotic.
Your fish get tail rot or a gaping wound or some body fungus, give them an antibiotic.
People will argue that antibiotics are bad and so forth......
I hope these people realize how many human lives antibiotics have saved since they were invented!!!!