Hi

This post is somewhat connected to another post:
http://forum.simplydiscus.com/showth...ve-dark-discus

Short story is some stuff is going on in my friends tank.
2 nights ago I noticed all his fish was hovering at the top in badly need of oxygen.
They have all been breathing fast and quite heavy, especially one of them.

Longer story:
I decided to try a prazi product. By my calculations and the direction on the bottle I'd end up with 2 ppm in the tank.
I'm sure I've read somewhere here on SD, that this is the right amount, so I dosed and kept an eye on things.
No effect, negative or positive, for several hours.
I spend the night on his couch and had an alarm set for the middle of the night just to check things.

Everything seemed calm, and no fish at the top.

This morning they all breath very slowly and easy and seem quite active. No hiding or clamped fins, very positive signs.

Questions:
Is 2 ppm prazi the right concentration?
Should I treat for 4 days (WC then add what was taking out)?
Re-treat after a 4 day since last dose?

There's plenty on info, but seems people are doing treatments very differently, so want to make sure I do things right.