According to Doctor Googly on the interweb thingy, the normal dosage for Sera Costapur is:
add 1 ml or 22 drops per 40 litres of water on the first and the 3 Day of the cure. In strong cases add also at day five and seven. Do not use UV sterilisers or filter carbon during the medication. A small increasing of the temperature with aeration of the aquarium water accelerates the process of healing. 50 ml sufficiently for 800 l water.
---------------------
No idea who writes this stuff but their gramma is like mine after lots of drinks.
---------------------
There should be a piece of paper in the box that contains the instructions. If not then dose it every second day, days 1, 3, 5 and 7.
Wipe the glass down and do a 90% water change and gravel clean the substrate before retreating the tank.
Remove carbon during treatment and increase aeration/ surface turbulence.
You don't have to turn up the temperature.
---------------------
Wash hands after handling the medication or working in the tank because it is pretty toxic. It contains Malachite Green, Formaldehyde and something else. Both of these chemicals kill protozoan infections and the male should get better within a few days.
*NB* Malachite Green is a known carcinogen (causes cancer) so keep it away from children and animals and wash hands with soapy water after use.
Keep medication in a cool dry place, away from sunlight so it doesn't break down too quickly.