Fin Rot

[Bazouteast]

I have three new Angel fish (approx 5cm height) which after two weeks in the tank appear to be showing signs of fin rot. I have looked at the usual suspects - water quality, overfeeding, temperature, overcrowding and conclude it is probably stress-related, following their introduction into the aquarium. They have good appetite and squabble, like most Angels.
I now have them in a treatment tank and I am using a proprietary brand of medication which appears to be Methelyn Blue.
My question is this....
This particular treatment requires 0.5ml/gallon. But it goes on..... "the dose may be repeated daily for up to five days". This worries me. Unless the medication somehow evaporates or dissapears in some way, after five days the concentration would be five times the recommended dose, which sounds dangerously high.
Anyone have experience of Methalene Blue treatment for Fin Rot?

 

[_PandorasBox_]

From what I've read about medicating fish, you need to do daily, 100% water changes, in order to flush out bacteria and waste and whatnot. I don't know if it's true, but it seems best for the fish anyways, as it would help get rid of whatever's wrong with them and get them fresh medication ( Though might freak them out )

 

[RainboWBacoN420]

Some good medication for fin rot would be Kanaplex, my girlfriend used it for her betta when he had fin rot. I'm currently using Kanaplex to treat my betta, which has a little bit of fin rot from when he bit his tail, a little while ago. Thankfully, it's not aggressive and it's very slow, so it should be easy to treat it. Just use activated carbon to soak up the meds out of the tank when you're done medicating. 
And as PandorasBox said, do major water changes, although I wouldn't say everyday, I would say at the end of the week, or twice per week. I personally don't like doing huge water changes like that, I think it could drastically effect the water and stress the fish out, I wouldn't do no more than 50% water changes. But of course, it's just a personal idea, do as you think is best.