Fungus and Finrot (what it sounds to be) is not columnaris (what it doesn't sound to be).
In this case I can't see any advantage for lowering or altering the temperature.
You shouldn't do a water change unless medication specifies that.
You can add venturi for extra aeration if you think the oxygen is low.
20... temp is 78... filter outflow increased... all fish, apart from Corys, now at surface and looking agitated... Corys are more frequently up to the surface too...not sure how - but it does happen......So could the lack of oxygen be due to the added Med?... How does that work?.. I can't think of anything else...
I had about 8-10 small trumpet snails suddenly appear on the glass, when i dosed with this stuff....I don't get it... and there are suddenly quite a few baby ramshorns snails that I'd not noticed before - all on the glass, near or at the waterline...
... seems like there's a lack of oxygen in the tank... or a poison?!... that's why I thought a water change?...
I had about 8-10 small trumpet snails suddenly appear on the glass, when i dosed with this stuff....I don't get it... and there are suddenly quite a few baby ramshorns snails that I'd not noticed before - all on the glass, near or at the waterline...
... seems like there's a lack of oxygen in the tank... or a poison?!... that's why I thought a water change?...
Some of the fish seemed to keep to the higher areas of the tank too.
Assuming this was a sign of lack of oxygen, i angled the internal filter so it made more bubbles/ripples.
I think I was too late for the suspect fish, but all the others are now back to normal (about 3 days after dose)