My fish have finrot and as advised, I have done a water change and then started treatment. I have removed the carbon filter.

However, my fish have risen to the top of the tank - is this normal? The treatment advised to dissolve it fully in warm water and add it on to the surface of the water.

Can anyone please tell me what's happening?

Thanks

What is the name and brand of the medication?
What size tank and how much water did you change?
What type fish?

the fish it's affecting most are our minnows. We also have 2 orandas. I did a 50% water change yesterday and again today before treatment. The treatment is interpret anti fungus and finrot. Have a 60L tank and gave just over 10ml dosage. (50ml = 10ml dosage)

I'm afraid I'm not familiar with that brand of medication.
Sometimes medication treatments are harder on the little fish, such as your minnows.
Do you have an air stone with lots of bubbles going into the water?
The more oxygen in the water the better.

If you have no air stone lower the water enough so that the water flowing back into the tank from the filter creates bubbles. This will supply the tank with more oxygen.

If there is plenty of oxygen being delivered to the tank and the little fish are still having trouble, try using a 5 ml dose instead.

Hope everything turns out OK.